ML20169A607

Tn Americas LLC - Updated Final Safety Analysis Report for the NUHOMS Eos System, Revision 3, Appendix a

ML20169A607
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Site:	07201042
Issue date:	06/30/2020
From:	Orano USA, TN Americas LLC
To:	Office of Nuclear Material Safety and Safeguards
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ML20169A592	List: ML20169A593 ML20169A594 ML20169A604 ML20169A605 ML20169A607
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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A A.1 GENERAL INFORMATION ................................................................................ A.1-1 A.1.1 Introduction.............................................................................................A.1-2 A.1.2 General Description and Operational Features of the NUHOMS MATRIX .............................................................................A.1-3 A.1.2.1 NUHOMS MATRIX Characteristics .................................... A.1-3 A.1.2.2 Transfer Equipment ............................................................... A.1-4 A.1.2.3 Operational Features ............................................................. A.1-5 A.1.3 Drawings..................................................................................................A.1-7 A.1.4 NUHOMS EOS System Contents .........................................................A.1-8 A.1.5 Qualification of TN Americas, LLC (Applicant) ...................................A.1-9 A.1.6 Quality Assurance .................................................................................A.1-10 A.1.7 References .............................................................................................A.1-11 A.1.8 Supplemental Data ................................................................................A.1-12 A.1.8.1 Generic Storage Arrays ....................................................... A.1-12 A.2 PRINCIPAL DESIGN CRITERIA ....................................................................... A.2-1 A.2.1 SSCs Important to Safety ........................................................................A.2-2 A.2.1.1 Dry Shielded Canisters .......................................................... A.2-2 A.2.1.2 HSM-MX ................................................................................ A.2-2 A.2.1.3 ISFSI Basemat and Approach Slabs ...................................... A.2-2 A.2.1.4 Transfer Equipment ............................................................... A.2-2 A.2.1.5 Auxiliary Equipment .............................................................. A.2-2 A.2.2 Spent Fuel To Be Stored .........................................................................A.2-3 A.2.3 Design Criteria for Environmental Conditions and Natural Phenomena ..............................................................................................A.2-4 A.2.3.1 Tornado Wind and Tornado Missiles for HSM-MX .............. A.2-4 A.2.3.2 Tornado Wind and Tornado Missiles for EOS-TC ................ A.2-4 A.2.3.3 Water Level (Flood) Design................................................... A.2-5 A.2.3.4 Seismic Design ....................................................................... A.2-5 A.2.3.5 Snow and Ice Loading ............................................................ A.2-6 A.2.3.6 Tsunami .................................................................................. A.2-6 Page A-i

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.2.3.7 Lightning ................................................................................ A.2-6 A.2.4 Safety Protection Systems .......................................................................A.2-7 A.2.4.1 General .................................................................................. A.2-7 A.2.4.2 Structural ............................................................................... A.2-7 A.2.4.3 Thermal .................................................................................. A.2-7 A.2.4.4 Shielding/Confinement/Radiation Protection ........................ A.2-8 A.2.4.5 Criticality ............................................................................... A.2-8 A.2.4.6 Material Selection .................................................................. A.2-8 A.2.4.7 Operating Procedures ............................................................ A.2-9 A.2.4.8 Acceptance Tests and Maintenance ....................................... A.2-9 A.2.4.9 Decommissioning ................................................................... A.2-9 A.2.5 References .............................................................................................A.2-10 A.3 STRUCTURAL EVALUATION ........................................................................... A.3-1 A.3.1 Structural Design ....................................................................................A.3-2 A.3.1.1 Design Criteria ...................................................................... A.3-2 A.3.2 Weight and Centers of Gravity ...............................................................A.3-3 A.3.3 Mechanical Properties of Materials .......................................................A.3-4 A.3.3.1 EOS-37PTH DSC/EOS-89BTH DSC ..................................... A.3-4 A.3.3.2 HSM-MX ................................................................................ A.3-4 A.3.3.3 EOS-TC .................................................................................. A.3-4 A.3.4 General Standards for NUHOMS MATRIX System ...........................A.3-5 A.3.4.1 Chemical and Galvanic Reaction .......................................... A.3-5 A.3.4.2 Positive Closure ..................................................................... A.3-5 A.3.4.3 Lifting Devices ....................................................................... A.3-5 A.3.4.4 Heat ........................................................................................ A.3-5 A.3.4.5 Cold ........................................................................................ A.3-7 A.3.5 Fuel Rods General Standards for NUHOMS MATRIX System ......................................................................................................A.3-8 A.3.6 Normal Conditions of Storage and Transfer .........................................A.3-9 A.3.6.1 EOS-37PTH DSC/89BTH DSC.............................................. A.3-9 A.3.6.2 HSM-MX ................................................................................ A.3-9 A.3.6.3 EOS-TC ................................................................................ A.3-10 Page A-ii

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.7 Off-Normal and Hypothetical Accident Conditions of Storage and Transfer ............................................................................A.3-11 A.3.7.1 EOS-37PTH DSC/89BTH DSC............................................ A.3-11 A.3.7.2 HSM-MX .............................................................................. A.3-11 A.3.7.3 EOS-TC ................................................................................ A.3-11 A.3.8 References .............................................................................................A.3-12 A.3.9.1 DSC SHELL STRUCTURAL ANALYSIS .................................................... A.3.9.1-1 A.3.9.1.1 General Description ..........................................................................A.3.9.1-1 A.3.9.1.2 DSC Shell Assembly Stress Analysis ................................................A.3.9.1-1 A.3.9.1.3 DSC Shell Buckling Evaluation .......................................................A.3.9.1-4 A.3.9.1.4 DSC Fatigue Analysis .......................................................................A.3.9.1-4 A.3.9.1.5 DSC Weld Flaw Size Evaluation ......................................................A.3.9.1-4 A.3.9.1.6 Conclusions .......................................................................................A.3.9.1-4 A.3.9.1.7 References .........................................................................................A.3.9.1-5 A.3.9.2 EOS-37PTH AND EOS-89BTH BASKET STRUCTURAL ANALYSIS ........................................................................................................ A.3.9.2-1 A.3.9.3 NUHOMS EOS SYSTEM ACCIDENT DROP EVALUATION ............... A.3.9.3-1 A.3.9.4 HSM-MX STRUCTURAL ANALYSIS.......................................................... A.3.9.4-1 A.3.9.4.1 General Description ..........................................................................A.3.9.4-1 A.3.9.4.2 Material Properties ...........................................................................A.3.9.4-1 A.3.9.4.3 Design Criteria ..................................................................................A.3.9.4-1 A.3.9.4.4 Load Cases.........................................................................................A.3.9.4-2 A.3.9.4.5 Load Combination.............................................................................A.3.9.4-2 A.3.9.4.6 Finite Element Models ......................................................................A.3.9.4-2 A.3.9.4.7 Normal Operation Structural Analysis ............................................A.3.9.4-4 A.3.9.4.8 Off-Normal Operation Structural Analysis .....................................A.3.9.4-5 A.3.9.4.9 Accident Condition Structural Analysis ...........................................A.3.9.4-6 A.3.9.4.10 Structural Evaluation .....................................................................A.3.9.4-11 A.3.9.4.11 Conclusions .....................................................................................A.3.9.4-21 A.3.9.4.12 References .......................................................................................A.3.9.4-22 Page A-iii

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.5 NUHOMS EOS-TC BODY STRUCTURAL ANALYSIS .......................... A.3.9.5-1 A.3.9.6 NUHOMS EOS FUEL CLADDING EVALUATION ................................. A.3.9.6-1 A.3.9.7 NUHOMS MATRIX STABILITY ANALYSIS ........................................... A.3.9.7-1 A.3.9.7.1 General Description ..........................................................................A.3.9.7-1 A.3.9.7.2 HSM-MX Stability Analyses .............................................................A.3.9.7-4 A.3.9.7.3 EOS Transfer Cask Missile Stability and Stress Evaluation ........A.3.9.7-14 A.3.9.7.4 References .......................................................................................A.3.9.7-15 A.4 THERMAL EVALUATION .................................................................................. A.4-1 A.4.1 Discussion of Decay Heat Removal System ...........................................A.4-2 A.4.2 Material and Design Limits ....................................................................A.4-3 A.4.2.1 Summary of Thermal Properties of Materials ....................... A.4-3 A.4.3 Thermal Loads and Environmental Conditions ....................................A.4-4 A.4.4 Thermal Evaluation for Storage ............................................................A.4-5 A.4.4.1 EOS-37PTH DSC and Basket Type 4H - Description of Load Cases for Storage.......................................................... A.4-6 A.4.4.2 EOS-37PTH DSC with Basket Type 4H - Thermal Model for Storage in HSM-MX .............................................. A.4-7 A.4.4.3 EOS-37PTH DSC with Basket Type 4H for HLZC 7 -

Storage Evaluation............................................................... A.4-17 A.4.4.4 EOS-37PTH DSC with Basket Type 4L/5 - Storage in HSM-MX .............................................................................. A.4-22 A.4.4.5 EOS-89BTH DSC with Basket Type 3 - Storage in HSM-MX .............................................................................. A.4-26 A.4.5 Thermal Evaluation for Storage in Updated HSM-MX ......................A.4-27 A.4.5.1 Design Changes in Updated HSM-MX ................................ A.4-27 A.4.5.2 Description of Load Cases for Storage in Updated HSM-MX .............................................................................. A.4-28 A.4.5.3 Thermal Model for Storage in Updated HSM-MX .............. A.4-28 A.4.5.4 EOS-37PTH DSC with Basket Type 4H - Storage in Updated HSM-MX ............................................................... A.4-29 A.4.5.5 EOS-37PTH DSC with Basket Type 4L/5 - Storage in Updated HSM-MX ............................................................... A.4-31 Page A-iv

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.5.6 EOS-89BTH DSC with Basket Type 3 - Storage in Updated HSM-MX ............................................................... A.4-32 A.4.5.7 Sensitivity Study ................................................................... A.4-33 A.4.6 References .............................................................................................A.4-38 A.5 CONFINEMENT .................................................................................................... A.5-1 A.6 SHIELDING EVALUATION ................................................................................ A.6-1 A.6.1 Discussions and Results ..........................................................................A.6-2 A.6.2 Source Specification ...............................................................................A.6-4 A.6.2.1 Computer Programs............................................................... A.6-4 A.6.2.2 PWR and BWR Source Terms ................................................ A.6-4 A.6.2.3 Axial Source Distributions and Subcritical Neutron Multiplication......................................................................... A.6-4 A.6.2.4 Control Components .............................................................. A.6-4 A.6.2.5 Blended Low Enriched Uranium Fuel ................................... A.6-4 A.6.2.6 Reconstituted Fuel ................................................................. A.6-4 A.6.2.7 Irradiation Gases ................................................................... A.6-4 A.6.3 Model Specification.................................................................................A.6-5 A.6.3.1 Material Properties ................................................................ A.6-5 A.6.3.2 MCNP Model Geometry for the EOS-TC .............................. A.6-5 A.6.3.3 MCNP Model Geometry for the HSM-MX............................. A.6-5 A.6.4 Shielding Analysis ...................................................................................A.6-8 A.6.4.1 Computer Codes..................................................................... A.6-8 A.6.4.2 Flux-to-Dose Rate Conversion .............................................. A.6-8 A.6.4.3 EOS-TC Dose Rates ............................................................... A.6-8 A.6.4.4 HSM-MX Dose Rates ............................................................. A.6-8 A.6.5 Supplemental Information....................................................................A.6-11 A.6.5.1 References ............................................................................ A.6-11 A.7 CRITICALITY EVALUATION ........................................................................... A.7-1 A.8 MATERIALS EVALUATION .............................................................................. A.8-1 A.8.1 General Information ...............................................................................A.8-2 A.8.1.1 HSM-MX Materials ................................................................ A.8-2 Page A-v

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.8.1.2 Environmental Conditions ..................................................... A.8-2 A.8.1.3 Engineering Drawings ........................................................... A.8-2 A.8.2 Materials Selection..................................................................................A.8-3 A.8.2.1 Applicable Codes and Standards and Alternatives ................ A.8-3 A.8.2.2 Material Properties ................................................................ A.8-4 A.8.2.3 Materials for ISFSI Sites with Experience of Atmospheric Chloride Corrosion........................................... A.8-5 A.8.2.4 Weld Design and Inspection .................................................. A.8-5 A.8.2.5 Galvanic and Corrosive Reactions ........................................ A.8-6 A.8.2.6 Creep Behavior of Aluminum................................................. A.8-6 A.8.2.7 Bolt Applications.................................................................... A.8-7 A.8.2.8 Protective Coatings and Surface Treatments ........................ A.8-7 A.8.2.9 Neutron Shielding Materials .................................................. A.8-7 A.8.2.10 Materials for Criticality Control ........................................... A.8-7 A.8.2.11 Concrete and Reinforcing Steel ............................................. A.8-7 A.8.2.12 Seals ....................................................................................... A.8-7 A.8.2.13 Low Temperature Ductility of Ferritic Steels ........................ A.8-7 A.8.3 Fuel Cladding..........................................................................................A.8-8 A.8.4 Prevention of Oxidation Damage During Loading of Fuel ..................A.8-9 A.8.5 Flammable Gas Generation..................................................................A.8-10 A.8.6 DSC Closure Weld Testing ...................................................................A.8-11 A.8.7 References .............................................................................................A.8-12 A.9 OPERATING PROCEDURES .............................................................................. A.9-1 A.9.1 Procedures for Loading the DSC and Transfer to the HSM-MX ...........................................................................................................A.9-2 A.9.1.1 TC and DSC Preparation....................................................... A.9-2 A.9.1.2 DSC Fuel Loading ................................................................. A.9-2 A.9.1.3 DSC Drying and Backfilling .................................................. A.9-2 A.9.1.4 DSC Sealing Operations ........................................................ A.9-2 A.9.1.5 TC Downending and Transfer to ISFSI ................................. A.9-2 A.9.1.6 DSC Transfer to the HSM-MX ............................................... A.9-2 A.9.1.7 Monitoring Operations .......................................................... A.9-4 A.9.2 Procedures for Unloading the DSC........................................................A.9-5 Page A-vi

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.9.2.1 DSC Retrieval from the HSM-MX.......................................... A.9-5 A.9.2.2 Removal of Fuel from the DSC .............................................. A.9-7 A.9.3 References ...............................................................................................A.9-8 A.10 ACCEPTANCE TESTS AND MAINTENANCE PROGRAM ........................ A.10-1 A.10.1 Acceptance Tests ...................................................................................A.10-2 A.10.1.2 Leak Tests............................................................................. A.10-2 A.10.1.3 Visual Inspection and Non-Destructive Examinations ........ A.10-2 A.10.1.4 Shielding Tests ..................................................................... A.10-2 A.10.1.5 Neutron Absorber Tests ....................................................... A.10-2 A.10.1.6 Thermal Acceptance Tests ................................................... A.10-3 A.10.1.7 Low Alloy High Strength Steel for Basket Structure ............ A.10-3 A.10.1.8 Cask Identification ............................................................... A.10-3 A.10.2 Maintenance Program ..........................................................................A.10-4 A.10.3 Repair, Replacement, and Maintenance ..............................................A.10-5 A.10.4 References .............................................................................................A.10-6 A.11 RADIATION PROTECTION ............................................................................. A.11-1 A.11.1 Radiation Protection Design Features .................................................A.11-2 A.11.2 Occupational Dose Assessment ............................................................A.11-3 A.11.2.1 EOS-DSC Loading, Transfer, and Storage Operations ....... A.11-3 A.11.2.2 EOS-DSC Retrieval Operations........................................... A.11-3 A.11.2.3 Fuel Unloading Operations ................................................. A.11-4 A.11.2.4 Maintenance Operations ...................................................... A.11-4 A.11.2.5 Doses during ISFSI Expansion ............................................ A.11-4 A.11.3 Offsite Dose Calculations .....................................................................A.11-5 A.11.3.1 Normal Conditions (10 CFR 72.104) .................................. A.11-5 A.11.3.2 Accident Conditions (10 CFR 72.106) ................................. A.11-8 A.11.4 Ensuring that Occupational Radiation Exposures Are ALARA ..................................................................................................A.11-9 A.11.4.1 Policy Considerations .......................................................... A.11-9 A.11.4.2 Design Considerations ......................................................... A.11-9 A.11.4.3 Operational Considerations................................................. A.11-9 A.11.5 References ...........................................................................................A.11-10 Page A-vii

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.12 ACCIDENT ANALYSES ..................................................................................... A.12-1 A.12.1 Introduction...........................................................................................A.12-1 A.12.2 Off-Normal Events ................................................................................A.12-2 A.12.2.1 Off-Normal Transfer Load ................................................... A.12-2 A.12.2.2 Extreme Temperatures ......................................................... A.12-4 A.12.3 Postulated Accidents .............................................................................A.12-5 A.12.3.1 EOS-TC Drop....................................................................... A.12-5 A.12.3.2 Earthquake ........................................................................... A.12-7 A.12.3.3 Tornado Wind and Tornado Missiles Effect on HSM-MX ........................................................................................ A.12-7 A.12.3.4 Tornado Wind and Tornado Missiles Effect on EOS-TC..... A.12-9 A.12.3.5 Flood .................................................................................... A.12-9 A.12.3.6 Blockage of HSM-MX Air Inlet Openings ........................... A.12-9 A.12.3.7 Lightning ............................................................................ A.12-10 A.12.3.8 Fire/Explosion.................................................................... A.12-10 A.12.4 References ...........................................................................................A.12-12 A.13 OPERATING CONTROLS AND LIMITS ........................................................ A.13-1 Page A-viii

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.1 GENERAL INFORMATION Table of Contents A.1 GENERAL INFORMATION ...................................................................................... A.1-1 A.1.1 Introduction ....................................................................................................... A.1-2 A.1.2 General Description and Operational Features of the NUHOMS MATRIX ....................................................................................... A.1-3 A.1.2.1 NUHOMS MATRIX Characteristics ................................................. A.1-3 A.1.2.2 Transfer Equipment ............................................................................. A.1-4 A.1.2.3 Operational Features ............................................................................ A.1-5 A.1.3 Drawings ............................................................................................................ A.1-7 A.1.4 NUHOMS EOS System Contents .................................................................. A.1-8 A.1.5 Qualification of TN Americas, LLC (Applicant) ........................................... A.1-9 A.1.6 Quality Assurance ........................................................................................... A.1-10 A.1.7 References ........................................................................................................ A.1-11 A.1.8 Supplemental Data .......................................................................................... A.1-12 A.1.8.1 Generic Storage Arrays ...................................................................... A.1-12 Page A.1-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Tables Table A.1-1 Key Design Parameters of the NUHOMS MATRIX Components ............. A.1-13 Page A.1-ii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Figures Figure A.1-1 NUHOMS MATRIX Construction Joint Expansion ................................... A.1-14 Figure A.1-2 NUHOMS MATRIX Expansion Joint ......................................................... A.1-15 Figure A.1-3 Not Used ........................................................................................................ A.1-16 Figure A.1-4 ISFSI Layout Drawing for Single Array ........................................................ A.1-17 Figure A.1-5 ISFSI Layout Drawing for a Double Array ................................................... A.1-18 Figure A.1-6 ISFSI Layout Drawing for a Combined Single and Double Array ................ A.1-19 Figure A.1-7 NUHOMS MATRIX System Components and Structures ......................... A.1-20 Figure A.1-8 NUHOMS MATRIX System Components and Structures ......................... A.1-21 Figure A.1-9 NUHOMS MATRIX System Components, Structures, and Transfer Equipment ...................................................................................................... A.1-22 Page A.1-iii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.1 GENERAL INFORMATION Appendix A to the NUHOMS EOS Updated Final Safety Analysis Report (UFSAR) addresses the Important to Safety aspects of adding the NUHOMS MATRIX (HSM-MX) to the NUHOMS EOS System described in the UFSAR. The HSM-MX is added to the UFSAR as an alternative to the EOS horizontal storage module (EOS-HSM). The primary reason for adding HSM-MX is to reduce the footprint of the current EOS-HSM, which will allow for greater storage capability on an independent spent fuel storage installation (ISFSI) pad than that currently available.

The HSM-MX is a two-tiered staggered, high-density horizontal storage module (HSM), which contains compartments to accommodate dry shielded canisters (DSCs) with various diameters and lengths (See Figure A.1-7 and Figure A.1-8). The HSM-MX provides an independent, passive system with heat removal capacity sufficient to ensure that peak cladding temperatures during long-term storage of spent fuel assemblies remain below acceptable limits to ensure fuel cladding integrity.

The format of this appendix has been prepared in compliance with the information and methods defined in Revision 1 to U.S. Nuclear Regulatory Commission (NRC)

NUREG-1536 [A.1-2]. The analyses presented in this appendix demonstrate that the HSM-MX System meets all the requirements of 10 CFR Part 72 [A.1-1].

Note: References to sections or chapters within this appendix are identified with a prefix A (e.g., Section A.2.3, Appendix A.2.3, Chapter A.2, or Appendix A.2).

References to sections or chapters of the UFSAR outside of this Appendix (i.e., main body of the UFSAR) are identified with the applicable UFSAR section or chapter number (e.g., Section 2.3 or Chapter 2).

Where the term HSM is used without distinction, this term shall be use applies to both the EOS-HSM and HSM-MX.

Page A.1-1 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.1.1 Introduction This appendix adds the HSM-MX to the NUHOMS EOS System. Only those features that are being revised or added to the NUHOMS EOS System are addressed and evaluated in this appendix. Sections of this appendix that are not affected by the addition of the HSM-MX are indicated in this appendix with No Change. The various DSCs and transfer cask (TC) in the NUHOMS EOS System remain generally unchanged.

The HSM-MX is a staggered, two-tiered reinforced monolithic structure, consisting of massive reinforced concrete compartments that increase resistance to earthquakes and offer significant self-shielding. The HSM-MX is capable of withstanding all normal condition loads, as well as the off-normal condition loads created by earthquakes, tornadoes, flooding, and other natural phenomena hazards. The DSCs are axially restrained to prevent movement during seismic events.

The system is equipped with special design features for enhanced shielding and heat rejection capabilities.

The HSM-MXs are arranged in arrays and fully expandable to permit modular expansion in support of operating power plants. The HSM-MX can be arranged in either a single-row or back-to-back arrangement. The thick concrete monolith of the HSM-MX provides substantial neutron and gamma shielding.

Page A.1-2 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.1.2 General Description and Operational Features of the NUHOMS MATRIX A.1.2.1 NUHOMS MATRIX CHARACTERISTICS The NUHOMS MATRIX provides a staggered two-tiered self-contained modular structure for storage of spent fuel canistered in an EOS-37PTH or EOS-89BTH DSC.

The HSM-MX is constructed from reinforced concrete and structural steel. Contact doses for the HSM-MX are designed to be as low as reasonably achievable (ALARA).

The key design parameters of the HSM-MX are listed in Table A.1-1.

In lieu of a separate roof and separate shield walls, those features are integral to the monolith in the HSM-MX.

The HSM-MXs provide an independent, passive system with substantial structural capacity to ensure the safe dry storage of spent fuel assemblies (SFAs). To this end, the HSM-MXs are designed to ensure that normal transfer operations and postulated accidents or natural phenomena do not impair the DSC or pose a hazard to the public or plant personnel. Postulated accidents and natural phenomena affecting the HSM-MX are described in detail in Chapter A.12.

The HSM-MX provides a means of removing spent fuel decay heat by a combination of radiation, conduction, and convection. Ambient air enters the HSM-MX through ventilation inlet openings located on the lower tier of the HSM-MX, circulates around the DSC and the heat shields, then exits through the outlets of the HSM-MX. The HSM-MX is designed to remove up to 50.0 kW of decay heat from the bounding EOS-37PTH DSC, when loaded in an HSM-MX lower compartment.

Decay heat is rejected from the DSC to the HSM-MX air space by convection and then removed from the HSM-MX by natural circulation airflow. Heat is also radiated from the DSC surface to the heat shields and HSM-MX walls and roof, where the natural convection airflow and conduction through the walls and roof aid in the removal of the decay heat. The passive cooling system for the HSM-MX is designed to preserve fuel cladding integrity by maintaining SFA peak cladding temperatures below acceptable limits during long-term storage. The outlet vent covers installed on the top of the HSM-MX are designed to mitigate the effect of sustained winds.

Configurations of systems to be stored in the HSM-MX are determined based on heat load, basket type, etc. These configurations are detailed in Table 1-2.

The HSM-MXs are installed on a load-bearing foundation, which consists of a reinforced concrete basemat on a subgrade suitable to support the loads. The HSM-MXs are not tied to the basemat.

Dimensions of the HSM-MX components described in the text and provided in figures and tables of this UFSAR are, in general, nominal dimensions for general system description purposes. Actual design dimensions are contained in the drawings in Section A.1.3.

Page A.1-3 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.1.2.2 TRANSFER EQUIPMENT Transfer Trailer:

The EOS DSC will be transferred to the HSM-MX using the same transfer trailer and ram as the transfer equipment transferring the EOS DSC to the EOS-HSM. Thus, there is no change from Section 1.2.2.

Cask Support Skid:

A universal support skid will be used for the transfer of the NUHOMS EOS DSC to the HSM-MX and is shown in Figure A.1-9. The key design features from the EOS cask support skid are the same as those described in Section 1.2.2; however, in addition, the universal support skid also allows for a NUHOMS MATRIX loading crane (MX-LC) to capture the skid with a grappling mechanism to raise and lower the TC/DSC for insertion into the HSM-MX.

Ram:

The EOS DSC will be transferred to the HSM-MX using the same ram as the transfer equipment transferring the EOS DSC to the EOS-HSM. Thus, there is no change from Section 1.2.2.

NUHOMS MATRIX Loading Crane:

The MX-LC is the device used as part of the NUHOMS transfer equipment, designed and built to assist in loading the DSC into the HSM-MX. The MX-LC is a Part 72

[A.1-1] important-to-safety (ITS)-related piece of transfer equipment. The MX-LC is designed, fabricated, installed, tested, inspected, and qualified in accordance with ASME NOG-1 [A.1-4], as a Type 1 gantry crane. In addition, the MX-LC is engineered to be single-failure-proof per NUREG-0612 [A.1-5]. The MX-LC is considered ITS as it supports the loaded TC/DSC during the DSCs insertion and extraction both into and out of the HSM-MX, respectively, thus providing both a structural and retrieval function.

NUHOMS MATRIX Retractable Roller Tray:

The NUHOMS MATRIX retractable roller tray (MX-RRT) is part of the NUHOMS transfer equipment and is a device used to support the DSC during transfer operations.

There are two MX-RRT beams inserted into opposing channels below the DSC opening on the HSM-MX. Each of the MX-RRT beams are removed upon completion of the loading operation.

Page A.1-4 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The MX-RRT is designed in accordance with ASME B30.1 [A.1-6] as a combination power-operated jack with industrial rollers. Structural acceptance criteria of the MX-RRT are in accordance with ASME NOG-1 [A.1-4]. In addition, the MX-RRT is engineered as single-failure-proof per NUREG-0612 [A.1-5]. The MX-RRT function is twofold, first to accept the DSC during its insertion, and second, to lower the DSC onto its permanent pillow blocks within the HSM-MX. The MX-RRT is a Part 72 ITS-related piece of transfer equipment. The MX-RRT is considered ITS since it supports the DSC during its insertion and extraction both into and out of the HSM-MX, respectively, thus providing both a structural and retrieval function.

MX-RRT Handling Device The MX-RRT handling device (RHD) is part of the NUHOMS Transfer Equipment and is a device used to allow insertion and extraction of the MX-RRT and the HSM-MX shield door shielding blocks. This is a NITS piece of equipment since it does not provide a safety function feature for the HSM-MX.

A.1.2.3 OPERATIONAL FEATURES This section provides a discussion of the sequence of operations involving the HSM-MX components.

A.1.2.3.1 Spent Fuel Assembly Loading Operations For the HSM-MX, there is no change from the primary operations listed in Steps 1 to 16 in Section 1.2.3.1. After those steps, the following operations occur, which replace Steps 17 to 20 in Section 1.2.3.1:

17. Move loaded TC to ISFSI

18. Position and align TC/HSM-MX

19. Insert DSC into HSM-MX

20. Close HSM-MX These operations from Steps 17 to 20 are described in the following paragraphs. The descriptions are intended to be generic and are described in greater detail in Chapter A.9. Plant-specific requirements may affect these operations and are to be addressed by the licensee.

Move Loaded Transfer Cask to ISFSI:

The transfer trailer is moved to the ISFSI along a predetermined route on a prepared road surface. Upon entering the ISFSI, the cask is positioned in front of the HSM-MX loading crane.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Position and align TC/HSM-MX:

The trailer is moved inside the HSM-MX loading crane, and the crane grappling mechanism captures the TC along with the skid.

The HSM-MX loading crane travels laterally and vertically to position the TC in front of its storage compartment in the open HSM-MX with MX-RRTs installed.

Insert DSC into HSM-MX:

After final alignment of the TC, HSM-MX, and ram, the DSC is slid onto the MX-RRT beams inside the HSM-MX by the ram. The DSC is then lowered into place onto the front and rear DSC supports.

Close HSM-MX:

Install HSM-MX door.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.1.3 Drawings MX01-5000-SAR NUHOMS HSM-MX HORIZONTAL STORAGE MODULE -

MATRIX Main Assembly (17 Sheets)

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Proprietary and Security Related Information for Drawing MX01-5000-SAR, Rev. 0 Withheld Pursuant to 10 CFR 2.390

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.1.4 NUHOMS EOS System Contents No change to Section 1.4.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.1.5 Qualification of TN Americas, LLC (Applicant)

The prime contractor for design and procurement of the NUHOMS MATRIX is TN Americas, LLC (TN). TN will subcontract the fabrication, testing, onsite construction, and quality assurance (QA) services, as necessary, to qualified firms on a project-specific basis, in accordance with TNs QA Program requirements.

The design activities for the SAR were performed by TN and subcontractors, in accordance with TN QA Program requirements. TN is responsible for the design and analysis of the HSM-MX and the associated transfer equipment.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.1.6 Quality Assurance TN Americas LLCs QA Program has been established in accordance with the requirements of 10 CFR Part 72, Subpart G [A.1-1]. The QA Program applies to the design, purchase, fabrication, handling, shipping, storing, cleaning, assembly, inspection, testing, operation, maintenance, repair, and modification of the NUHOMS MATRIX and components identified as ITS and safety-related. These components and systems are defined in Chapter A.2.

The complete description and specific commitments of the TN Americas LLC QA program are contained in the TN Americas LLC QA Program Description Manual

[A.1-3]. This manual has been approved by the NRC for performing 10 CFR Part 72-related activities.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.1.7 References A.1-1 Title 10, Code of Federal Regulations, Part 72, Licensing Requirements for the Independent Storage of Spent Nuclear Fuel, High-Level Radioactive Waste, and Reactor-Related Greater Than Class C Waste.

A.1-2 NUREG-1536, Standard Review Plan for Spent Fuel Dry Storage Systems at a General License Facility, Revision 1, U.S. Nuclear Regulatory Commission, Office of Nuclear Material Safety and Safeguards, July 2010.

A.1-3 TN Americas, LLC, TN Americas LLC Quality Assurance Program Description Manual for 10 CFR Part 71, Subpart H and 10 CFR Part 72, Subpart G, current revision.

A.1-4 ASME NOG-1-2015, Rules for Construction of Overhead and Gantry Cranes (Top Running Bridge Multiple Girder), The American Society of Mechanical Engineers, New York, New York, 2015.

A.1-5 NUREG-0612, Control of Heavy Loads at Nuclear Power Plants, U.S. Nuclear Regulatory Commission, July 1980.

A.1-6 ASME B30.1-2015, Jacks, Industrial Rollers, Air Casters, and Hydraulic Gantries, The American Society of Mechanical Engineers, New York, New York, 2015.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.1.8 Supplemental Data A.1.8.1 GENERIC STORAGE ARRAYS The DSC containing the SFAs is transferred to, and stored in, compartments of the HSM-MX. Multiple compartments are grouped together to form a staggered, two-tiered monolithic structure known as the HSM-MX. Multiple compartments are grouped together to form arrays whose size is determined to meet plant-specific needs.

The HSM-MX is arranged within the ISFSI site on a concrete basemat(s) with the entire area enclosed by a security fence. Modules may be placed in a single-row array or in a back-to-back array for site dose and footprint optimization. Like the EOS-HSM, the decay heat within the HSM-MX DSC compartment is primarily removed by internal natural circulation flow though the inlet/outlet vents and conduction through the HSM-MX walls.

Figure A.1-1 and Figure A.1-2 show typical HSM-MX expansion layouts at ISFSIs that are capable of modular expansion to any capacity.

The expansion option shown in Figure A.1-1 allows the array to be expanded with a construction joint splitting the upper compartment at the end of the array. A minimum of five compartments are required in a monolith. End shield walls shall be installed at this location in the interim period between expansions; the shield walls will be removed to allow for expansion of the array. Two empty compartments (one upper and one lower), in addition to the partial empty compartment, are required at the end of an array during the interim period before expansion. At the end of the array, the end wall will be the same thickness as the wall at the beginning of the first array, and all compartments may be filled.

Figure A.1-2 shows the expansion joint used at ~100 feet into the array. This joint addresses the thermal growth due to cyclic temperatures in ambient conditions. When an array is expanded at the expansion joint, two empty compartments (one top and one bottom) are required at the end of the interim array prior to expansion. When the expansion joint is used, and construction continues past the expansion joint, the construction joint configuration can be used to further expand the array, or the array can terminate with an end wall the same thickness as the wall at the beginning of the first array. If using the construction joint configuration, the same requirements described above for the construction joint apply.

These are typical layouts only and do not represent limitations in number of modules, number of rows, and orientation of modules in rows. Back-to-back module configurations require expansion in sets of pairs. Expansion can be accomplished, as necessary, by the licensee, provided the criteria of 10 CFR 72.104, 10 CFR 72.106 and Chapter 14 are met. The parameters of interest in planning the installation layout are the configuration of the HSM-MX array and an area in front of each HSM-MX to provide adequate space for loading operations. Illustrations of typical HSM-MX ISFSI layouts are provided in Figure A.1-4 through Figure A.1-6.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.1-1 Key Design Parameters of the NUHOMS MATRIX Components Horizontal Storage Module (HSM-MX):

23-1 single array Overall length 41-4 back-to-back array Overall width 36-6 Overall height (two-tiers without vent 27-1 3/8 covers)

Total weight not including DSC (kips) 2,450 (single array)

(max. concrete density of 160 pcf.) 4,125 (double array)

Materials of construction Reinforced concrete and structural steel Heat removal Conduction, convection, and radiation Note: Dimensions are based on a single monolith of five compartments (see Figure A.1-2).

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.1-1 NUHOMS MATRIX Construction Joint Expansion Page A.1-14 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.1-2 NUHOMS MATRIX Expansion Joint Page A.1-15 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.1-3 Not Used Page A.1-16 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.1-4 ISFSI Layout Drawing for Single Array Page A.1-17 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.1-5 ISFSI Layout Drawing for a Double Array Page A.1-18 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.1-6 ISFSI Layout Drawing for a Combined Single and Double Array Page A.1-19 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.1-7 NUHOMS MATRIX System Components and Structures Page A.1-20 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.1-8 NUHOMS MATRIX System Components and Structures Page A.1-21 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.1-9 NUHOMS MATRIX System Components, Structures, and Transfer Equipment Page A.1-22 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.2 PRINCIPAL DESIGN CRITERIA Table of Contents A.2 PRINCIPAL DESIGN CRITERIA ............................................................................. A.2-1 A.2.1 SSCs Important to Safety .............................................................................. A.2-2 A.2.1.1 Dry Shielded Canisters ..................................................................... A.2-2 A.2.1.2 HSM-MX .......................................................................................... A.2-2 A.2.1.3 ISFSI Basemat and Approach Slabs ................................................. A.2-2 A.2.1.4 Transfer Equipment .......................................................................... A.2-2 A.2.1.5 Auxiliary Equipment ......................................................................... A.2-2 A.2.2 Spent Fuel To Be Stored ................................................................................ A.2-3 A.2.3 Design Criteria for Environmental Conditions and Natural Phenomena...................................................................................................... A.2-4 A.2.3.1 Tornado Wind and Tornado Missiles for HSM-MX ........................ A.2-4 A.2.3.2 Tornado Wind and Tornado Missiles for EOS-TC ........................... A.2-4 A.2.3.3 Water Level (Flood) Design ............................................................. A.2-5 A.2.3.4 Seismic Design.................................................................................. A.2-5 A.2.3.5 Snow and Ice Loading ...................................................................... A.2-6 A.2.3.6 Tsunami............................................................................................. A.2-6 A.2.3.7 Lightning ........................................................................................... A.2-6 A.2.4 Safety Protection Systems ............................................................................. A.2-7 A.2.4.1 General .............................................................................................. A.2-7 A.2.4.2 Structural ........................................................................................... A.2-7 A.2.4.3 Thermal ............................................................................................. A.2-7 A.2.4.4 Shielding/Confinement/Radiation Protection ................................... A.2-8 A.2.4.5 Criticality .......................................................................................... A.2-8 A.2.4.6 Material Selection ............................................................................. A.2-8 A.2.4.7 Operating Procedures ........................................................................ A.2-9 A.2.4.8 Acceptance Tests and Maintenance .................................................. A.2-9 A.2.4.9 Decommissioning ............................................................................. A.2-9 A.2.5 References ..................................................................................................... A.2-10 Page A.2-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Tables Table A.2-1 NUHOMS EOS HSM-MX System Major Components and Safety Classification.................................................................................................. A.2-12 Table A.2-2 Thermal Conditions for NUHOMS HSM-MX System Analyses ............... A.2-13 Page A.2-ii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Figures Figure A.2-1 RG 1.60 Response Spectra with Enhancement in Frequencies above 9.0 Hz ................................................................................................................... A.2-14 Page A.2-iii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.2 PRINCIPAL DESIGN CRITERIA This section provides the principal design criteria for the NUHOMS MATRIX (HSM-MX) described in Chapter A.1. Section A.2.1 identifies the structures, systems, and components (SSCs) important-to-safety (ITS) for the HSM-MX design. Section A.2.2 presents a general description of the spent fuel to be stored. Section A.2.3 provides the design criteria for environmental conditions and natural phenomena.

Section A.2.4 discusses safety protection systems.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.2.1 SSCs Important to Safety Table 2-1 provides a list of major NUHOMS EOS System independent spent fuel storage installation (ISFSI) components and their classification. In addition, Table A.2-1 provides a list of the major NUHOMS MATRIX (HSM-MX) components and their classification. Components are classified in accordance with the criteria of 10 CFR Part 72. Structures, systems, and components (SSCs) classified as important-to-safety (ITS) are defined in 10 CFR 72.3 as the features of the ISFSI whose function is:

To maintain the conditions required to store spent fuel safely.

To prevent damage to the spent fuel container during handling and storage.

To provide reasonable assurance that spent fuel can be received, handled, packaged, stored, and retrieved without undue risk to the health and safety of the public.

These criteria are applied to the HSM-MX components in determining their classification in the paragraphs that follow.

A.2.1.1 Dry Shielded Canisters No Change to Section 2.1.1 A.2.1.2 HSM-MX The HSM-MX is considered ITS since it provides physical protection and shielding for the dry shielded canister (DSC) during storage. The reinforced concrete HSM-MX is designed in accordance with American Concrete Institute (ACI) 349-06 [A.2-3] and constructed to ACI-318-08 [A.2-4]. The level of testing, inspection, and documentation provided during construction and maintenance is in accordance with the quality assurance requirements as defined in 10 CFR Part 72 [A.2-6], Subpart G and as described in Chapter 14. Thermal instrumentation for monitoring HSM-MX concrete temperatures is considered not important-to-safety (NITS).

A.2.1.3 ISFSI Basemat and Approach Slabs The independent spent fuel storage installation (ISFSI) basemat and approach slabs and buildings for indoor storage are considered NITS and are designed, constructed, maintained, and tested as commercial-grade items.

Licensees are required to perform an assessment to confirm that the license seismic criteria described in Section A.2.3.4 are met.

A.2.1.4 Transfer Equipment A.2.1.4.1 Transfer Cask and Yoke No change to Section 2.1.4.1.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.2.1.4.2 Other Transfer Equipment The NUHOMS EOS HSM-MX transfer equipment (i.e., ram, skid, transfer trailer, MATRIX loading crane (MX-LC), MATRIX retractable rolling tray (MX-RRT) and MX-RRT handling device (RHD)) are necessary for the successful loading of the DSCs into the HSM-MX.

MX-LC The NUHOMS MX-LC is the device used as part of the NUHOMS transfer equipment, designed and built to assist in loading the DSC into the HSM-MX. The MX-LC is a Part 72 [A.2-6] ITS-related piece of transfer equipment. The MX-LC is designed, fabricated, installed, tested, inspected, and qualified in accordance with ASME NOG-1 [A.2-7], as a Type I gantry crane. In addition, the MX-LC is engineered as single-failure-proof per NUREG-0612 [A.2-9]. The MX-LC is considered ITS since it supports the loaded TC/DSC during the DSCs insertion and extraction both into and out of the HSM-MX, respectively, thus providing both a structural and retrieval function.

MX-RRT The MX-RRT is part of the NUHOMS transfer equipment and is a device used to support the DSC, during transfer operations. There are two MX-RRT beams inserted into opposing channels below the DSC opening on the HSM-MX. Each of the MX-RRT beams are removed upon completion of the loading operation and replaced with the HSM-MX shield door shielding blocks. The MX-RRT is designed in accordance with ASME B30.1 [A.2-15] as a combination power-operated jack with industrial rollers. Structural acceptance criteria of the MX-RRT is in accordance with ASME NOG-1 [A.2-7]. In addition, the MX-RRT is engineered as single-failure-proof per NUREG-0612 [A.2-9]. The MX-RRT function is twofold, one to accept the DSC during its insertion and second, to lower the DSC onto its permanent pillow blocks within the HSM-MX. The MX-RRT is a Part 72 ITS-related piece of transfer equipment. The MX-RRT is considered ITS as it supports the DSC during its insertion and extraction both into and out of the HSM-MX, respectively, thus providing both a structural and retrieval function.

MX-RRT Handling Device The MX-RRT handling device is part of the NUHOMS Transfer Equipment and is a device used to allow insertion and extraction of the MX-RRT and the HSM-MX shield door shielding blocks. This is a NITS piece of equipment since it does not provide a safety function feature for the HSM-MX.

A.2.1.5 Auxiliary Equipment No change to Section 2.1.5.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.2.2 Spent Fuel To Be Stored Spent fuel that is allowed for storage in the HSM-MX is described in Section 2.2.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.2.3 Design Criteria for Environmental Conditions and Natural Phenomena The HSM-MX ITS SSCs described in Section A.2.1 are designed consistent with the 10 CFR Part 72 [A.2-6] §122(b) requirement for protection against environmental conditions and natural phenomena. The criterion used in the design of the NUHOMS EOS System ensures that exposure to credible site hazards does not impair their safety functions.

A.2.3.1 Tornado Wind and Tornado Missiles for HSM-MX The HSM-MX and MX-LC are designed to safely withstand 10 CFR 72.122 (b)(2) tornado missiles. The tornado characteristics, as specified in NRC Regulatory Guide (RG) 1.76, Revision 1 [A.2-8], are used to qualify the HSM-MX and MX-LC. The missiles spectrum of NUREG-0800, Revision 3, Section 3.5.1.4 [A.2-10] with missile velocity for Region I is used to qualify the HSM-MX and MX-LC.

Extreme wind effects are much less severe than the specified design basis tornado (DBT) wind forces. The design basis extreme wind for the HSM-MX is calculated per

[A.2-10].

However, since the MX-LC is specified per ASME NOG-1 [A.2-7] loading conditions, the design basis wind for the MX-LC is calculated per Region IV of

[A.2-12]. Nonetheless, congruent with the HSM-MX, the design basis extreme wind (i.e., tornado wind) for the MX-LC is calculated per Region I of [A.2-10].

A.2.3.1.1 Tornado Wind Design Parameters No change to Section 2.3.1.1.

A.2.3.1.2 Determination of Forces on Structures No change to Section 2.3.1.2.

A.2.3.1.3 Tornado Missiles No change to Section 2.3.1.3.

A.2.3.2 Tornado Wind and Tornado Missiles for EOS-TC No change to Section 2.3.2.

A.2.3.2.1 Tornado Wind Design Parameters No change to Section 2.3.2.1.

A.2.3.2.2 Tornado Missiles No change to Section 2.3.2.2.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.2.3.3 Water Level (Flood) Design HSM-MX inlet vents are blocked when the depth of flooding is greater than 0.25 m (10 in.) for the lower compartment, and 2.29 m (7 ft-6 in.), for the upper compartments, above the level of the ISFSI basemat. The DSC in the lower and upper compartments are wetted when flooding exceeds a depth of 1.3 m (4 ft-2 in.), and 4.4 m (14 ft-5 in.), respectively, above ISFSI basemat. Greater flood heights result in submersion of the DSC and blockage of the HSM-MX outlet vents.

The DSC and HSM-MX are conservatively designed for an enveloping design basis flood. The flood is postulated to result from natural phenomena such as tsunamis and seiches, as specified by 10 CFR 72.122(b) [A.2-6]. A bounding assumption of a 15-meter (50-foot) flood height and water velocity of 4.6 m/sec (15 fps) is used for the flood evaluation. The HSM-MX is evaluated for the effects of the 4.6 m/sec (15 fps) water current impinging upon the side of the submerged HSM-MX. The DSC is subjected to an external pressure equivalent to a 15-meter (50-foot) head of water.

These evaluations are presented in Section A.12.3.5. The effects of water reflection on DSC criticality safety are addressed in Chapter 7. Due to its short-term, infrequent use, the onsite EOS transfer cask (EOS-TC) is not explicitly evaluated for flood effects. Independent spent fuel storage installation procedures should ensure that the EOS-TC is not used for DSC transfer during flood conditions.

The plant-specific design basis flood (if the possibility for flooding exists at a particular ISFSI site) should be evaluated by the licensee and shown to be enveloped by the flooding conditions used for this generic evaluation of the HSM-MX.

A.2.3.4 Seismic Design The seismic design criteria for the HSM-MX are based on the NRC RG 1.60 [A.2-13]

response spectra anchored at a zero period acceleration (ZPA) of 0.85g in the horizontal direction and 0.80g in the vertical direction and enhanced frequency content above 9 Hz. The horizontal and vertical components of the design response spectra corresponding to a maximum horizontal ground acceleration of 1.0g are shown in Figure A.2-1. The seismic structural evaluations consider both stability evaluation and stress qualification of the HSM-MX. The stability criteria for seismic loading are based on the stability response of a five-compartment construction joint option of the HSM-MX module without the side shield walls attached.

The HSM-MX has no anchorage to the concrete basemat. The stability analyses consider the effects of sliding and rocking motions, and determine the maximum possible sliding of the HSM-MX. The HSM-MX will neither slide nor overturn at design ZPA of 0.48g in the horizontal direction and 0.32g in the vertical direction.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The licensee shall determine if, based on ISFSI-specific site investigations, a soil-structure interaction (SSI) analyses ought to be performed to assess potential site-specific amplifications. The SSI evaluations are based on ISFSI site-specific parameters (free-field accelerations, strain-dependent soil properties, HSM-MX array configurations, etc.). The SSI response spectra at the base of the HSM-MXs are to be bounded by the HSM-MX design basis seismic criteria response spectra, i.e., the RG 1.60 response spectra shape, with enhanced spectral accelerations above 9 Hz, and anchored at 0.85g horizontal and 0.80g vertical directions. The licensee shall reconcile spectral accelerations from the SSI analysis response spectra that exceed the seismic criteria spectra (if any); 5% damped response spectra may be used in making these determinations.

Since the DSC can be considered to act as a large diameter pipe for the purpose of evaluating seismic effects, the Equipment and Large Diameter Piping System category in NRC RG 1.61 [A.2-16], Table 1 is applicable. Therefore, a damping value of 3% of critical damping for the design bases safe shutdown earthquake is used.

Similarly, from the same RG table, a damping value of 7% of critical damping is used for the reinforced concrete structural components of the HSM-MX.

The seismic criteria for the MX-LC are based on Figures 1 and 2 of NRC Regulatory Guide 1.60 [A.2-13], with enhanced spectral accelerations above 9 Hz, and anchored at 0.85g zero period acceleration (ZPA) in the horizontal direction and 0.80g ZPA in the vertical direction. The seismic structural calculations consider both a stability evaluation and stress qualification of the MX-LC for seismic loading criteria. The stability evaluations address the MX-LC rails and use of any shims under the MX-LC rails due to unevenness in the basemat and approach slab foundation.

The seismic criteria for the MX-RRTs is based on Figures 1 and 2 of NRC Regulatory Guide 1.60 [A.2-13], with enhanced spectral accelerations above 9 Hz, and anchored at 0.85g ZPA in the horizontal direction and 0.80g ZPA in the vertical direction. As required, the seismic structural calculations shall consider both a stability evaluation and stress qualification for the seismic loading criteria.

A.2.3.5 Snow and Ice Loading No change to Section 2.3.5.

A.2.3.6 Tsunami No change to Section 2.3.6.

A.2.3.7 Lightning A lightning strike will not cause a significant thermal effect on the HSM-MX, MX-LC, MX-RRT, or stored DSC. The effects on the HSM-MX resulting from a lightning strike are discussed in Section 12.3.7.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.2.4 Safety Protection Systems A.2.4.1 General No change to Section 2.4.1.

A.2.4.2 Structural A.2.4.2.1 EOS-DSC Design Criteria No change to Section 2.4.2.1.

A.2.4.2.2 HSM-MX Design Criteria The principal design criteria for the HSM-MX, both the concrete and steel structures, are presented in Table 2-7.

The reinforced concrete HSM-MX is designed to meet the requirements of ACI 349-06 [A.2-3]. The ultimate strength method of analysis is utilized with the appropriate strength reduction factors as described in Appendix A.3.9.4. The load combinations specified in Section 6.17.3.1 of American National Standards Institute (ANSI) 57.9-1984 [A.2-20] are used for combining normal operating, off-normal, and accident loads for the HSM-MX. All seven load combinations specified are considered and the governing combinations are selected for detailed design and analysis. The resulting HSM-MX load combinations and the appropriate load factors are presented in Appendix A.3.9.4. The effects of duty cycle on the HSM-MX are considered and found to have negligible effect on the design.

A.2.4.2.3 EOS-TC Design Criteria No change to Section 2.4.2.3.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.2.4.2.4 MX-LC Design Criteria The MX-LC is designed in accordance with the applicable portions of ASME NOG-1

[A.2-7], as a Type 1 gantry style crane. The MX-LC is engineered to provide high integrity handling (HIH) of the load, defined as a lifting/handling operation, wherein the risk of an uncontrolled lowering of the heavy load is considered non-credible.

Demonstration of HIH of the MX-LC occurs when designed for single-failure-proof lifting operations per NUREG-0612 [A.2-9], maintaining the supported loads in a safe configuration during design basis events (e.g., seismic). Therefore, design requirements from ASME NOG-1 for Type 1 loading equipment are specified with an additional single failure proof handling capability. MX-LC single-failure-proof handling capability is achieved by ensuring that the applicable design factor is 200%

of that required by ASME NOG-1 (i.e., NUREG-0612 application). Alternatively, other load carrying members may be designed with redundant devices to meet the single failure proof handling capability. Therefore, MX-LC HIH may be achieved by having either MX-LC subcomponent SSCs that comply with ASME NOG-1 stress limits plus the 200% NUREG-0612 design factor or with other MX -LC subcomponent SSCs having redundant safety basis protection features.

A.2.4.2.5 MX-RRT Design Criteria Congruent with the MX-LC, the MX-RRT is engineered to provide HIH of the load.

Demonstration of HIH of the MX-RRT occurs when designed for single-failure-proof lifting operations per NUREG-0612 [A.2-9], maintaining the supported loads in a safe configuration during design basis events (e.g., seismic). Therefore, applicable design acceptance criteria are provided by ASME NOG-1 [A.2-7], plus an additional single-failure-proof handling capability. MX-RRT single failure proof handling capability is achieved by ensuring that the design factor is 200% of that from ASME NOG-1 (i.e., NUREG-0612 application). In lieu of the 200% requirement, it is acceptable to have other load carrying members designed with redundant devices to meet the single failure proof handling. Therefore, MX-RRT HIH may be achieved by having either MX-RRT subcomponent SSCs that comply with ASME NOG-1 stress limits plus the 200% NUREG-0612 design factor or with other MX-RRT subcomponent SSCs having redundant safety-basis protection features.

A.2.4.3 Thermal The NUHOMS MATRIX relies on natural convection through the air space in the HSM-MX to cool the DSC. This passive convective ventilation system is driven by the pressure difference due to the stack effect (Ps) provided by the height difference between the bottom of the DSC and the HSM-MX air outlet. This pressure difference is greater than the flow pressure drop (Pf) at the design air inlet and outlet temperatures. The details of the ventilation system design are provided in Chapter A.4.

Page A.2-9 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Thermal analysis is based on fuel assemblies with decay heat up to 50.0 kW per DSC for the EOS-37PTH and up to 34.4 kW per DSC for the EOS-89BTH. Zoning is used to accommodate high per assembly heat loads. The heat load zoning configurations for the DSCs are shown in Figure 1A through Figure 1I and Figure 2 of the Technical Specifications [A.2-18] for 37PTH and 89BTH DSC, respectively. Among the various HLZCs presented in Figure 1 for EOS-37PTH DSC, only HLZC # 7 through 9 presented in Figure 1G through Figure 1I are applicable for storage in HSM-MX.

Similarly for the EOS-89BTH, among the various HLZCs presented in Figure 2 for EOS-89BTH DSC, only HLZC # 3 is permitted for storage in the HSM-MX.

The thermal analyses for storage are performed for the environmental conditions listed in Table A.2-2. The remainder of the environment conditions are provided in Table 2-9.

Peak clad temperature of the fuel at the beginning of the long-term storage does not exceed 400 °C for normal conditions of storage, and for short-term operations, including DSC drying and backfilling. Fuel cladding temperature shall be maintained below 570 °C (1058 °F) for accident conditions involving fire or off-normal storage conditions.

For onsite transfer in the EOS-TC, air circulation may be used, as a recovery action, to facilitate transfer operations in the EOS-37PTH DSC as described in the Technical Specifications [A.2-18].

A.2.4.4 Shielding/Confinement/Radiation Protection The HSM-MX provides the bulk of the radiation shielding for the DSCs. The HSM-MX designs can be arranged in either a single-row or a back-to-back arrangement.

The nominal thickness of the HSM-MX roof is 50 inches for biological shielding.

Additionally, the front wall has a minimum thickness of 39 inches. Sufficient shielding is provided by thick concrete side walls between HSM-MXs in an array to minimize doses in adjacent HSM-MXs during loading and retrieval operations.

Section A.11.3 provides a summary of the offsite dose calculations for representative arrays of design basis HSM-MXs providing assurance that the limits in 10 CFR 72.104 and 10 CFR 72.106(b) are not exceeded.

There are no radioactive releases of effluents during normal and off-normal storage operations. Also, there are no credible accidents that cause significant releases of radioactive effluents from the DSC. Therefore, there are no off-gas or monitoring systems required for the HSM-MX.

A.2.4.5 Criticality No change to Section 2.4.5.

A.2.4.6 Material Selection No change to Section 2.4.6.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.2.4.7 Operating Procedures The sequence of operations are outlined for the HSM-MX in Chapter A.9 for loading of fuel, closure of the DSC, transfer to the ISFSI using the TC, insertion into the HSM-MX, monitoring operations, and retrieval and unloading. Throughout Chapter A.9, CAUTION statements are provided at the step where special notice is needed to maintain as low as reasonably achievable (ALARA), protect the contents of the DSC, protect the public and/or ITS components of the HSM-MX.

A.2.4.8 Acceptance Tests and Maintenance Chapter A.10 specifies the acceptance testing and maintenance program for ITS components of the HSM-MX.

A.2.4.9 Decommissioning The exact decommissioning plan for the ISFSI will be dependent on the U.S.

Department of Energys fuel transportation system capability and requirements for a specific plant. Because of the minimal contamination of the outer surface of the DSC, no contamination is expected on the internal passages of the HSM-MX. It is anticipated that the prefabricated HSM-MXs can be dismantled and disposed of using commercial demolition and disposal techniques.

Page A.2-11 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.2.5 References A.2-1 Title 10, Code of Federal Regulations, Part 100, Reactor Site Criteria.

A.2-2 American Society of Mechanical Engineers, ASME Boiler and Pressure Vessel Code,Section III, Division 1, Subsections NB, NF, ND and NCA, 2010 Edition with 2011 Addenda.

A.2-3 ACI 349-06, Code Requirements for Nuclear Safety Related Concrete Structures, American Concrete Institute.

A.2-4 ACI 318-08, Building Code Requirements for Structural Concrete and Commentary, American Concrete Institute.

A.2-5 Title 10, Code of Federal Regulations, Part 50, Domestic Licensing of Production and Utilization Facilities.

A.2-6 Title 10, Code of Federal Regulations, Part 72, Licensing Requirements for the Independent Storage of Spent Nuclear Fuel, High-Level Radioactive Waste, and Reactor-Related Greater Than Class C Waste.

A.2-7 ASME NOG-1-2015, Rules for Construction of Overhead and Gantry Cranes (Top Running Bridge Multiple Girder), The American Society of Mechanical Engineers, New York, New York, 2015.

A.2-8 U.S. Nuclear Regulatory Commission, Regulatory Guide 1.76, Design Basis Tornado and Tornado Missiles for Nuclear Power Plants, Revision 1, March 2007.

A.2-9 NUREG-0612, Control of Heavy Loads at Nuclear Power Plants, U.S. Nuclear Regulatory Commission, July 1980.

A.2-10 NUREG-0800, Standard Review Plan, Section 3.3.1 Wind Loading, Section 3.3.2 Tornado Loads, and Section 3.5.1.4 Missiles Generated by Tornado and Extreme Winds, Revision 3, March 2007.

A.2-11 NUREG-0800, Standard Review Plan, Section 3.5.3 Barrier Design Procedures, Revision 3, March 2007.

A.2-12 American Society of Civil Engineers, ASCE 7-10, Minimum Design Loads for Buildings and Other Structures, (formerly ANSI A58.1).

A.2-13 NRC Regulatory Guide 1.60, Design Response Spectra for Seismic Design of Nuclear Power Plants Revision 1, December 1973.

A.2-14 ANSI N14.6, American National Standard for Special Lifting Device for Shipping Containers Weighing 10,000 lbs. or More for Nuclear Materials, American National Standards Institute, Inc., 1993.

A.2-15 ASME B30.1-2015, Jacks, Industrial Rollers, Air Casters, and Hydraulic Gantries, The American Society of Mechanical Engineers, New York, New York, 2015.

A.2-16 U.S. Nuclear Regulatory Commission, Regulatory Guide 1.61, Damping Values for Seismic Design of Nuclear Power Plants, Revision 1, March 2007.

A.2-17 NOT USED Page A.2-12 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.2-18 CoC 1042 Appendix A, NUHOMS EOS System Generic Technical Specifications, Amendment 1.

A.2-19 NOT USED A.2-20 ANSI 57.9-1984, Design Criteria for an Independent Spent Fuel Storage Installation (Dry Type).

Page A.2-13 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.2-1 HSM-MX System Major Components and Safety Classification Component 10 CFR Part 72 Classification(1)

Horizontal Storage Module (HSM-MX)

Reinforced Concrete ITS Thermal Instrumentation (if used) NITS Transfer Equipment MX-LC ITS MX-RRT ITS Universal Support Skid ITS Notes:

1. SSCs ITS are defined in 10 CFR 72.3 as those features of the ISFSI whose function is (1) to maintain the conditions required to store spent fuel safely, (2) to prevent damage to the spent fuel container during handling and storage, or (3) to provide reasonable assurance that spent fuel can be received, handled, packaged, stored, and retrieved without undue risk to the health and safety of the public.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.2-2 Thermal Conditions for HSM-MX System Analyses Operating EOS-37PTH/EOS-89BTH DSC Minimum Ambient Maximum Ambient Conditions Location Temperature Temperature Normal HSM-MX -20 °F 100 °F Off-Normal HSM-MX -40 °F 117 °F (1)

Accident HSM-MX n/a 117 °F Notes:

1. 10% rod rupture is considered for this blocked vent accident condition for DSC internal pressure calculation.

Page A.2-15 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 RG 1.60 (3%, Horiz.

Enhanced)

RG 1.60 Response Spectrum @ 1.0g ZPA Freq (Hz) Acc. (g)

Horizontal Direction (3% & 7% Damping) 0.10 0.085 0.25 0.529 10.000 2.5 3.755 9.0 3.130 16.0 2.885 Spectral Acceleration (g) 45.0 1.000 1.000 100.0 1.000 RG 1.60 (7%, Horiz.

Enhanced)

Freq (Hz) Acc. (g) 0.10 0.069 0.100 0.25 0.432 RG 1.60 (7%) 2.5 2.720 RG 1.60 (7%) Enhanced 9.0 2.270 RG 1.60 (3%)

16.0 2.093 RG 1.60 (3%) Enhanced 0.010 45.0 1.000 0.1 1.0 10.0 100.0 100.0 1.000 Frequency (Hz)

HORIZONTAL RG 1.60 (3%, Vert.

Enhanced)

RG 1.60 Response Spectrum @ 1.0g ZPA Freq (Hz) Acc. (g)

Vertical (3% & 7% Damping) 0.10 0.056 0.25 0.353 3.5 3.577 10.000 9.0 3.130 20.0 2.797 Spectral Acceleration (g) 45.0 1.000 100.0 1.000 1.000 RG 1.60 (7%, Vert.

Enhanced)

Freq (Hz) Acc. (g) 0.10 0.046 0.100 0.25 0.287 RG 1.60 (7%) 3.5 2.590 RG 1.60 (7%) Enhanced RG 1.60 (3%) 9.0 2.270 RG 1.60 (3%) Enhanced 20.0 2.030 0.010 45.0 1.000 0.1 1.0 10.0 100.0 100.0 1.000 Frequency (Hz)

VERTICAL Figure A.2-1 RG 1.60 Response Spectra with Enhancement in Frequencies above 9.0 Hz Page A.2-16 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.3 STRUCTURAL EVALUATION Table of Contents A.3 STRUCTURAL EVALUATION ................................................................................. A.3-1 A.3.1 Structural Design ........................................................................................... A.3-2 A.3.1.1 Design Criteria .................................................................................. A.3-2 A.3.2 Weight and Centers of Gravity ..................................................................... A.3-3 A.3.3 Mechanical Properties of Materials ............................................................. A.3-4 A.3.3.1 EOS-37PTH DSC/EOS-89BTH DSC .............................................. A.3-4 A.3.3.2 HSM-MX .......................................................................................... A.3-4 A.3.3.3 EOS-TC............................................................................................. A.3-4 A.3.4 General Standards for NUHOMS MATRIX System ............................... A.3-5 A.3.4.1 Chemical and Galvanic Reaction ...................................................... A.3-5 A.3.4.2 Positive Closure ................................................................................ A.3-5 A.3.4.3 Lifting Devices.................................................................................. A.3-5 A.3.4.4 Heat ................................................................................................... A.3-5 A.3.4.5 Cold ................................................................................................... A.3-7 A.3.5 Fuel Rods General Standards for NUHOMS MATRIX System ............................................................................................................. A.3-8 A.3.6 Normal Conditions of Storage and Transfer ............................................... A.3-9 A.3.6.1 EOS-37PTH DSC/89BTH DSC ....................................................... A.3-9 A.3.6.2 HSM-MX .......................................................................................... A.3-9 A.3.6.3 EOS-TC........................................................................................... A.3-10 A.3.7 Off-Normal and Hypothetical Accident Conditions of Storage and Transfer ................................................................................................. A.3-11 A.3.7.1 EOS-37PTH DSC/89BTH DSC ..................................................... A.3-11 A.3.7.2 HSM-MX ........................................................................................ A.3-11 A.3.7.3 EOS-TC........................................................................................... A.3-11 A.3.8 References ..................................................................................................... A.3-12 Page A.3-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Tables Table A.3-1 Summary of HSM-MX Weight and Center of Gravity ................................. A.3-13 Page A.3-ii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3 STRUCTURAL EVALUATION This chapter and its appendices describe the structural evaluation for the NUHOMS MATRIX (HSM-MX), described in Appendix A.1, under normal and off-normal conditions, accident conditions, and natural phenomena events. Structural evaluations are provided for the important-to-safety components (ITS), which are the EOS-37PTH DSC, the EOS-89BTH DSC, and the HSM-MX monolith. The analyses in Chapter 3 of the EOS-TCs envelop the HSM-MX system and are therefore not provided in this chapter.

Page A.3-1 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.1 Structural Design The HSM-MX is a staggered horizontal storage version of the NUHOMS EOS System, which provides environmental protection and radiological shielding for the DSCs. The HSM-MX is designed to accommodate EOS-37PTH DSC and 89BTH DSC configurations. The HSM-MX provides heat rejection from the spent fuel decay heat. Sections in this section of the Appendix that do not have an effect on the evaluations presented in Chapter 3 of the Updated Final Safety Analysis Report (UFSAR) include a statement that there is no change. In addition, a complete evaluation of the HSM-MX has been performed and is summarized in this section and appendices, which are ITS in accordance with 10 CFR Part72 [A.3-1].

A.3.1.1 Design Criteria A.3.1.1.1 EOS-37PTH DSC/EOS-89BTH DSC Design Criteria No change to Section 3.1.1.1.

A.3.1.1.1.1 Stress Criteria No change to Section 3.1.1.1.1.

A.3.1.1.1.2 Stability Criteria No change to Section 3.1.1.1.2.

A.3.1.1.2 HSM-MX Design Criteria The HSM-MX concrete and steel components are designed to the requirements of American Concrete Institute (ACI) 349-06 [A.3-2] and the American Institute of Steel Construction (AISC) Manual of Steel Construction [A.3-3], respectively, meeting the load combinations in accordance with the requirements of ANSI 57.9 [A.3-4]. The load combination and design criteria for concrete components are described in Appendix A.3.9.4.

A.3.1.1.3 EOS-TC Design Criteria No change to Section 3.1.1.3.

Page A.3-2 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.2 Weight and Centers of Gravity Table A.3-1 summarizes the weights of the HSM-MX. The dead weights of the components are determined based on the nominal dimensions.

Page A.3-3 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.3 Mechanical Properties of Materials A.3.3.1 EOS-37PTH DSC/EOS-89BTH DSC No change to Section 3.3.1.

A.3.3.2 HSM-MX The material properties for the HSM-MX are summarized in Chapter A.8.

A.3.3.3 EOS-TC No change to Section 3.3.3.

Page A.3-4 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.4 General Standards for NUHOMS MATRIX System A.3.4.1 Chemical and Galvanic Reaction No change to Section 3.4.1 for the EOS System. Chemical and galvanic reactions for the HSM-MX System are presented in Chapter A.8.

A.3.4.2 Positive Closure No change to Section 3.4.2.

A.3.4.3 Lifting Devices No change to Section 3.4.3.

A.3.4.4 Heat A.3.4.4.1 Summary of Pressures and Temperatures Temperatures and pressures for the HSM-MX are described in Chapter A.4. The thermal evaluations for storage and transfer conditions are performed in Chapter A.4 for normal, off-normal, and accident conditions. The internal pressure evaluation is performed in Chapter A.4, Section A.4.5.

Maximum temperatures for the various components of the HSM-MX, loaded with an EOS-37PTH DSC or an EOS-89BTH DSC under normal, off-normal and accident conditions are summarized in Chapter A.4, Section A.4.5 for all the applicable heat zone loading configurations provided in Appendix A, Technical Specification [A.3-5].

These temperatures are used for the structural evaluations documented in Appendices A.3.9.1 and A.3.9.4. Stress allowables for the components are a function of component temperature. The temperatures used to perform the structural analyses are based on actual calculated temperatures or conservatively selected higher temperatures.

A.3.4.4.2 Differential Thermal Expansion No change to Section 3.4.4.2.

A.3.4.4.2.1 Minimum Gaps within the Interlocking Slots No change to Section 3.4.4.2.1.

A.3.4.4.2.2 Axial Gaps between the Basket Assembly Plates No change to Section 3.4.4.2.2.

A.3.4.4.2.3 Radial Gap between the Basket Assembly and the DSC Shell No change to Section 3.4.4.2.3.

Page A.3-5 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.4.4.2.4 Axial Gaps between Fuel Assemblies and the DSC Cavity No change to Section 3.4.4.2.4.

A.3.4.4.2.5 Axial Gap between the Basket Assembly and the DSC Cavity No change to Section 3.4.4.2.5.

A.3.4.4.2.6 Axial Gap between the Transition Rails and the DSC Cavity No change to Section 3.4.4.2.6.

A.3.4.4.2.7 Axial Gap between the TC125/TC135 Cavity and the DSC Shell No change to Section 3.4.4.2.7.

A.3.4.4.2.8 Axial Gap between the Rear DSC support, Axial Retainer and the HSM-MX cavity A gap of 0.5 inch is provided between the rear DSC Support and the HSM-MX to accommodate any thermal growth. This section verifies that there is no interference when the rear DSC support increases from room temperature to accident temperature.

The maximum temperature of the rear DSC support is assumed to be 350°F. A mean thermal expansion coefficient of 7.0x10-6 in/in/°F for 350°F is used. The thermal growth of the rear DSC support is determined as:

rs=xx rs=21.5x7.0x106x(35070)=0.042 .

The maximum thermal growth between the rear DSC Support and the HSM-MX is 0.042 inch and is less than the initial 0.5-inch gap.

Therefore, there is sufficient clearance for free thermal expansion between the rear DSC supports and HSM-MX.

A gap is provided between the axial retainer and DSC to accommodate any thermal growth. Shims are used to adjust the gap to be 0.1875 inch initially. The bounding thermal expansion temperature ranges from the normal operating temperature to the blocked vent accident temperature. The largest average temperature difference for the DSC is 396 °F - 293 °F = 103 °F. The axial retainer is conservatively assumed to experience the same temperature difference. The average HSM concrete temperature difference is 207 °F - 152 °F = 55 °F. Conservatively, a higher temperature difference of 105 °F is applied to the DSC and axial retainer, and a lower temperature difference of 50 °F is applied to the HSM concrete. Thermal expansion coefficients of 7.5 x 10-6 in/in/°F and 10.1 x 10-6 in/in/°F for 350 °F are used for the Axial Retainer and the DSC, respectively. The instantaneous coefficients of thermal expansion are used here as the initial temperatures are above 70 °F. A thermal expansion coefficient of 5.5 x 10-6 in/in/°F is used for the HSM concrete. The growth of the HSM is subtracted from the growth of the DSC and axial retainer as it increases the gap.

Page A.3-6 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20

= x x + x x x x

= 199.5 x 10.1 x 106 x (105) + 36.5 x 7.5 x 106 x (105) (199.5 +

36.5) x 5.5 x 106 x (50) = 0.175 in The maximum thermal growth between the axial retainer and DSC is 0.175 inch and is less than a 0.1875-inch gap.

A.3.4.5 Cold No change to Section 3.4.5.

Page A.3-7 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.5 Fuel Rods General Standards for NUHOMS MATRIX System No change to Section 3.5.

Page A.3-8 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.6 Normal Conditions of Storage and Transfer This section presents the structural analysis of the EOS-37PTH DSC/ EOS-89BTH DSCs, the HSM-MX and the EOS-TC subjected to normal conditions of storage and transfer. The analyses performed evaluate the components for the design criteria described in Section A.3.1.1.

Numerical analyses have been performed for the normal and accident conditions. In general, numerical analyses have been performed for the regulatory events. The analyses are summarized in this section.

The detailed structural analyses of the HSM-MX are included in Appendices A.3.9.1 through A.3.9.7.

A.3.6.1 EOS-37PTH DSC/89BTH DSC Details of the structural analysis of the DSC shell assemblies are provided in Appendix A.3.9.1, while the structural analysis for basket assemblies are provided in Appendix 3.9.2. There are no changes to the analysis described for the DSC shell except that the DSC shell is analyzed for dead weight and seismic load combinations, which are affected when the DSC is loaded into the HSM-MX and are provided in Appendix A.3.9.1. The design or loading conditions for the basket remain the same when loaded into the DSC shell and, therefore, results for the basket from Appendix 3.9.2 remain the same and are applicable.

A.3.6.2 HSM-MX The HSM-MX design is able to accommodate different DSC lengths. For the structural evaluation, the HSM-MX with the longest DSC bounds all sizes. The following table shows how the bounding loads are used for structural evaluation of the HSM-MX.

Component Weight (kips) Thermal Heat Load EOS-37PTH DSC 134 50 kW (Loaded Weight)

EOS-89BTH DSC 120 43.6 kW (Loaded Weight) 50 kW for lower Bounding HSM-MX (2) compartment and 41.8 4,125 (Double Array) kW for upper compartment (1)

Notes:

1. The thermal loading condition of the HSM-MX is based on the most conservative thermal loading configuration.

2. For stability evaluation, several different combinations of DSC and HSM bounding weights are considered.

Page A.3-9 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Detailed geometry descriptions, material properties, loadings, and structural evaluation for the HSM-MX are presented in Appendix A.3.9.4.

A.3.6.3 EOS-TC No change to Section 3.6.3.

Page A.3-10 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.7 Off-Normal and Hypothetical Accident Conditions of Storage and Transfer This section presents the structural analyses of the EOS-37PTH DSC, EOS-89BTH DSC and the HSM-MX subjected to off-normal and hypothetical accident conditions.

These analyses are summarized in this section, and described in detail in Appendices A.3.9.1 through A.3.9.7.

A.3.7.1 EOS-37PTH DSC/89BTH DSC Detailed geometry descriptions, material properties, loadings, and structural evaluation for the affected loads combinations of the DSC are presented in Appendix A.3.9.1.

The design and loading conditions for the basket remain the same when loaded into the DSC shell and, therefore, results for the basket from Appendix 3.9.2 remain the same and are applicable.

A.3.7.2 HSM-MX Detailed geometry descriptions, material properties, loadings, and structural evaluation for the HSM-MX are presented in Appendix A.3.9.4.

A.3.7.3 EOS-TC No change to Section 3.7.3.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.8 References A.3-1 Title 10, Code of Federal Regulations, Part 72, Licensing Requirements for the Storage of Spent Fuel in the Independent Spent Fuel Storage Installation, U.S. Nuclear Regulatory Commission.

A.3-2 ACI 349-06, Code Requirements for Nuclear Safety Related Concrete Structures, American Concrete Institute, November 2006.

A.3-3 American Institute of Steel Construction, AISC Manual of Steel Construction, 13th Edition or 14th Edition.

A.3-4 ANSI/ANS 57.9-1984, Design Criteria for an Independent Spent Fuel Storage Installation (Dry Storage Type), American National Standards Institute.

A.3-5 CoC 1042 Appendix A, NUHOMS EOS System Generic Technical Specifications, Amendment 1.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3-1 Summary of HSM-MX Weight and Center of Gravity Component Description Total Weight (kips)

Single Array 2,448 Double Array 4,125 Empty HSM-MX Center of Gravity from Bottom in Vertical Direction (inches)

Single Array 176.42 Double Array 178.79 Maximum Weight (kips)

Single Array 3,048 HSM-MX Loaded with Double Array 5,325 EOS-37PTH DSC Center of Gravity from Bottom in Vertical Direction (inches)

Single Array 168.68 Double Array 169.39 Maximum Weight (kips)

Single Array 3,053 HSM-MX Loaded with Double Array 5,335 EOS-89BTH DSC Center of Gravity from Bottom in Vertical Direction (inches)

Single Array 168.63 Double Array 169.33 Notes:

1. The weight and center of gravity values listed in the table are corresponding to the maximum concrete density of 160 pcf.

2. The weight values are for the HSM-MX having three lower compartments and two upper compartments.

Page A.3-13 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.3.9.1 DSC SHELL STRUCTURAL ANALYSIS Table of Contents A.3.9.1 DSC SHELL STRUCTURAL ANALYSIS .................................................... A.3.9.1-1 A.3.9.1.1 General Description .......................................................................... A.3.9.1-1 A.3.9.1.2 DSC Shell Assembly Stress Analysis ............................................... A.3.9.1-1 A.3.9.1.3 DSC Shell Buckling Evaluation........................................................ A.3.9.1-4 A.3.9.1.4 DSC Fatigue Analysis ....................................................................... A.3.9.1-4 A.3.9.1.5 DSC Weld Flaw Size Evaluation ...................................................... A.3.9.1-4 A.3.9.1.6 Conclusions ....................................................................................... A.3.9.1-4 A.3.9.1.7 References ......................................................................................... A.3.9.1-5 Page A.3.9.1-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Tables Table A.3.9.1-1 EOS-37PTH/EOS-89BTH DSC Shell Assembly Loads and Load Combinations .................................................................................... A.3.9.1-6 Table A.3.9.1-2 DSC Results - Load Combinations ................................................... A.3.9.1-9 Table A.3.9.1-3 DSC Weld Stress Results- Load Combinations .............................. A.3.9.1-11 Table A.3.9.1-4 DSC-OTCP Maximum Radial Weld Stress (Sx) Results- Load Combinations .................................................................................. A.3.9.1-12 Table A.3.9.1-5 Controlling DSC Load Combination Results Summary ................. A.3.9.1-13 Page A.3.9.1-ii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Figures Figure A.3.9.1-1 DSC Supports and Axial Retainers ................................................. A.3.9.1-14 Figure A.3.9.1-2 DSC Dead Weight Equivalent Pressure .......................................... A.3.9.1-15 Figure A.3.9.1-3 DSC Boundary Conditions in HSM-MX ........................................ A.3.9.1-16 Figure A.3.9.1-4 Internals Seismic Equivalent Pressures with Internal Pressure, Load Case 2..................................................................................... A.3.9.1-17 Page A.3.9.1-iii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.1 DSC SHELL STRUCTURAL ANALYSIS The purpose of this appendix is to present the structural evaluation of the shell assembly of the EOS-37PTH dry shielded canister (DSC) and the EOS-89BTH DSC under all applicable normal, off-normal and accident loading conditions during storage in the NUHOMS MATRIX (HSM-MX).

The DSC shell is evaluated in Chapter 3.9.1 for all loads and load combinations. Only dead weight, and seismic load combinations affect the DSC when stored in the HSM-MX. Therefore, results from Chapter 3.9.1 are applicable to this chapter except for dead weight and seismic load combinations.

A.3.9.1.1 General Description No change to Section 3.9.1.1.

A.3.9.1.2 DSC Shell Assembly Stress Analysis No change to Section 3.9.1.2.

A.3.9.1.2.1 Material Properties No change to Section 3.9.1.2.1.

A.3.9.1.2.2 DSC Shell Stress Criteria No change to Section 3.9.1.2.2.

A.3.9.1.2.3 Finite Element Model Description No change to Section 3.9.1.2.3 except that ANSYS version 17.1 [A.3.9.1-1] is used for the analysis in this appendix.

A.3.9.1.2.4 Mesh Sensitivity No change to Section 3.9.1.2.4.

A.3.9.1.2.5 Post-Processing No change to Section 3.9.1.2.5.

A.3.9.1.2.6 Stress Categorization Sensitivity Studies No change to Section 3.9.1.2.6.

A.3.9.1.2.7 Load Cases for DSC Shell Stress Analysis No change to Section 3.9.1.2.7, except the dead weight load as described in A.3.9.1.2.7.1 and the seismic loads as described in A.3.9.1.2.7.6.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.1.2.7.1 Dead Weight The dead weight is analyzed for the following basic configurations:

When the DSC is vertical in the EOS-TC135 (No change to Section 3.9.1.2.7.1),

When the DSC is horizontal in the EOS-TC135 (No change to Section 3.9.1.2.7.1),

When the DSC is horizontal in the HSM-MX.

The model for the HSM-MX differs from EOS-HSM in boundary conditions representing the DSC supports. The DSC supports and axial retainers are shown in Figure A.3.9.1-1.

Horizontal Position in HSM-MX When stored in the HSM-MX, the DSC shell is supported by the front and rear DSC supports. The inertial loads of the DSC internals are accounted for by applying an equivalent pressure onto the inner surface of the DSC shell. The magnitude of the pressure is determined based on the payload of 105 kips.

The interfaces between the DSC and the HSM-MX DSC supports, axial retainer and rear stop plate are modeled through node-to-node contact elements (CONTA178).

The nodes representing the HSM-MX supports are constrained in all Degrees of Freedom (DOF). Similarly, the stop plate and axial retainer are also constrained in all degrees of freedom.

Figure A.3.9.1-2 and Figure A.3.9.1-3 show the pressure load and boundary conditions applied to the Finite Element Model (FEM).

Gaps for the contact elements are set to zero, placing the DSC and the HSM-MX DSC supports in initial contact.

A.3.9.1.2.7.2 Fabrication Pressure and Leak Testing No change to Section 3.9.1.2.7.2.

A.3.9.1.2.7.3 Internal and External Pressure No change to Section 3.9.1.2.7.3.

A.3.9.1.2.7.4 HSM-MX Loading/Unloading No change to Section 3.9.1.2.7.4 except that the loads applied by the ram are balanced by the friction between the DSC shell and the EOS-TC and or MX-RRT support.

A.3.9.1.2.7.5 Transfer/Handling Load No change to Section 3.9.1.2.7.5.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.1.2.7.6 Seismic Load during Storage The model described in Section A.3.9.1.2.7.1 for dead weight in HSM-MX is used and updated to reflect the effect of the vertical 0.8g load, transverse 1.7g load, axial (longitudinal) 1.7g load, and the internal pressure load of 20 psig.

Two elastic-plastic runs are performed for this load:

1. 0.8g vertical + 1.7g transverse + 1.7g axial with the weight of DSC internals modeled by equivalent pressure application on TSP with addition of internal pressure of 20 psig.

2. 0.8g vertical + 1.7g transverse + 1.7g axial with the weight of DSC internals modeled by equivalent pressure application on IBCP with addition of internal pressure of 20 psig.

The compound effect of dead weight, 0.8g vertical and 1.7g transverse, is modeled by multiplying the pressure from the dead weight case by a conservative factor of 4.

Seismic axial forces away from the HSM-MX door (load case 1 above) are resisted by the rear plates located at the ends of the DSC rear supports. The OTCP is recessed from the edge of the DSC shell, thus, the rear plate bears against the bottom edge of the DSC shell. The nodes of the top end of DSC shell, which come into contact with the rear stop plate, are restrained in the axial direction.

Seismic axial forces toward the HSM-MX door (load case 2 above) are resisted by the front axial retainers. The retainer is a steel bar located horizontally through the HSM-MX door. The retainer bears against the OBCP. The nodes of the OBCP, which bear against the area of the axial retainer bar, are restrained in the axial direction.

Figure A.3.9.1-4 shows the pressure load applied to the DSC while supported by the HSM-MX DSC supports.

The DSC shell and the OBCP experience compressive bearing stress in the vicinity of the axial retainer and rear plate. The bearing stresses experienced by the DSC shell and OBCP need not be evaluated for Service Level D loads.

A.3.9.1.2.7.7 Cask Drop No change to Section 3.9.1.2.7.7.

A.3.9.1.2.7.8 Thermal Loads Thermal analysis is performed to support the new HLZCs 4, 5, 6, 7, 8 and 9 as discussed in Technical Specification [A.3.9.1-2] (See Figure 1D through Figure 1I).

For thermal stress analysis, temperature profiles and maximum component temperatures are based on thermal analysis of the EOS-37PTH DSC for transfer conditions. For transfer operations, HLZC 4 bounds HLZC 5, 6, 7, 8 and 9. The new HLZC 4 DSC maximum temperature is 480 °F (Chapter 4, Figure 4.9.6-4) which is below the temperatures of 484 °F (Chapter 4, Figure 4-32) for transfer operation.

Therefore, new HZLC temperatures are bounded by the original thermal stress analysis. Therefore, no change to Section 3.9.1.2.7.8.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.1.2.8 Load Combinations No change to Section 3.9.1.2.8, except the dead weight and seismic load combinations described in Section A.3.9.1.2.7. Table A.3.9.1-1 provides the load combinations described in Section 3.9.1.2.8, in this chapter for information purpose. Only load combinations 9 and 10 affecting the DSC stored in HSM-MX on the front and rear DSC supports are analyzed.

A.3.9.1.3 DSC Shell Buckling Evaluation No change to Section 3.9.1.3.

A.3.9.1.4 DSC Fatigue Analysis No change to Section 3.9.1.4.

A.3.9.1.5 DSC Weld Flaw Size Evaluation No change to Section 3.9.1.5.

A.3.9.1.6 Conclusions The EOS DSC shell assembly has been analyzed for normal, off-normal, and accident load conditions using three dimensional finite element analyses. The load combinations provided in Section A.3.9.1.2.8 are used in the analysis of the EOS DSC. Analyses are performed only for the dead weight and seismic load combinations (9 and 10), which affect the DSC when stored in the HSM-MX. Stress intensities in different components of the DSC shell assembly, compared with ASME code stress intensity allowables and the resulting stress ratios, are summarized in Table A.3.9.1-2. The stress ratio is calculated by dividing the maximum stress intensity by the stress intensity allowable value, with the stress ratio required to be less than 1.

The DSC weld stresses are summarized in Table A.3.9.1-3. The maximum weld stress ratio is 0.87 and occurs at the DSC shell to ITCP weld for Load Combination 9. The maximum radial weld stress is summarized in Table A.3.9.1-4. The maximum radial stress between the DSC and OTCP is 4.22 ksi. Therefore, the flaw size evaluation from Section 3.9.1.5 still remains valid.

Table A.3.9.1-5 summarizes the stress results for the controlling load combination.

The maximum component stress ratio remains the same as in the original analysis and is equal to 0.92 in the grapple ring support. The second maximum component stress ratio is equal to 0.87 and occurs in the confinement boundary area of the DSC shell during load combination 9 (storage condition in the HSM-MX, dead weight normal conditions).

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The structural integrity of the DSC shell, including closure welds, is maintained since the maximum stress ratio is less than 1. Therefore, it is concluded that the EOS DSC is structurally adequate under all anticipated load conditions for service during the transfer and storage in the HSM-MX.

A.3.9.1.7 References A.3.9.1-1 ANSYS Computer Code and Users Manual, Release 14.0, Release 14.0.3 and Release 17.1 A.3.9.1-2 CoC 1042 Appendix A, NUHOMS EOS System Generic Technical Specifications, Amendment 1.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.1-1 EOS-37PTH/EOS-89BTH DSC Shell Assembly Loads and Load Combinations (2 Sheets)

Load DSC Load for Service Loading Type Load Combination Combination Orientation Analysis Level No.

Dead weight 1g down (axial)

(DW)

Blowdown/ 20 psig internal DW+ Normal Pressure Test Vertical(1) pressure Pressure+ Normal A 1 Normal vertical Thermal(2)

Thermal orientation thermal Dead weight 1g down (DW)

Thermal-Off Off-Normal -Hot DW + H +

Normal Hot (117 °F) Pressure+ Thermal 2

Thermal-Off Off-Normal Cold (117 °F)

Normal Cold Horizontal(3) (-40 °F) A Internal Pressure- DW + H +

20 psig 3 Off Normal Pressure+ Thermal

(-40 °F)

Handling in H=+/- 1g axial+/- 1 g transfer cask trans.+/-1 g vertical (H)(15)

Dead weight 1g down (DW) DW+ Ram (135 Ram Loads 135 kips (push) , (5) kips insertion)+

4 (push/pull) 80 kips (pull)(6) Pressure +Thermal (3) (7)

Horizontal A/B Internal pressure- DW + Ram (80 20 psig(9) 5 Off-Normal kips, retrieval) +

ThermalOff Thermal -Off Pressure + Thermal Normal Normal(8)

Dead weight 1g down (DW) DW + Ram (135 Ram Loads (pull) Horizontal(3) 135 kips(6) kips retrieval) + D 6 Internal pressure- Pressure 20 psig(9)

Off-Normal Page A.3.9.1-6 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.1-1 EOS-37PTH/EOS-89BTH DSC Shell Assembly Loads and Load Combinations (2 Sheets)

Load DSC Load for Service Loading Type Load Combination Combination Orientation Analysis Level No.

Dead Weight 1g down (DW) 7A Internal pressure- Horizontal(3) 20 psig(9) DW + Pressure+ 65 Off-Normal D Vertical(3) inch Accident Drop Accident Side/corner 65 inch drop 7B drop(17)

Dead Weight 1g down (DW) DW + Accident Horizontal D 8 Internal pressure- (3)(9)(10) Pressure 130 psig Accident Dead Weight 1g down (DW)

Internal Pressure- Horizontal DW + Pressure+

(11) 20 psig A 9 Off-Normal Thermal Thermal-Off Thermal-Off Normal Normal Dead Weight 1g down (DW)

Internal Pressure-Horizontal 20 psig DW + Pressure+

Off-Normal (11) D 10 Seismic (S)

S=+/-1.7g(axial)

Seismic (S) +/-1.7g(transverse

+/-0.8g(vertical)(16)

Test Pressure at 23 psig (15x1.5=23 23 psig internal fabricator23 Vertical psig) internal Test 11 pressure psig(12) pressure External pressure Horizontal See Note (14) D 12 Notes

1. DSC in Transfer cask in vertical orientation. Only inner top cover is installed.

2. Use bounding thermal case for normal operations of transfer cask in vertical orientation.

3. DSC in Transfer Cask; Transfer Cask is in horizontal orientation. In case of End drop, the orientation is vertical supported by IBS in case of Bottom End drop and TSP in case of Top End drop.

4. Not used.

5. The push loads are applied at the canister bottom surface within the grapple ring support.

6. The pull loads are applied at the inner surface of the grapple ring.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20

7. Level B evaluations may take credit for 10% increase in allowable per NB-3223(a). Level B is used for the case with internal pressure. Level A is used for the case without internal pressure.

8. Use controlling thermal off-normal case.

9. Load combination results to bound cases with and without internal pressure. Use bounding pressure of HSM blocked vent accident or transfer cask accident fire conditions.

10. Use bounding pressure of HSM blocked vent accident or transfer cask accident fire conditions.

11. DSC in HSM supported on the DSC supports.

12. Conservatively use 23 psig as the test pressure; test configuration is circular shell and inner bottom welded to shell; a top end lid with a155 kips clamping force may be used to seal the test assembly.

13. Not Used.

14. The maximum accident condition external pressure before DSC collapse/buckling is to be determined from the analysis.

15. These handling loads in conjunction with Level A limits bounds case of transfer cask in fuel building under seismic loads (Level D accident condition).

16. Unless lower g loads can be justified based on frequency analysis of HSM loaded with bounding DSC.

17. The top end drop and bottom end drop are not credible events under 10 CFR Part 72, therefore these drop analyzes are not required. However, consideration of end drops (for 10 CFR Part 71 conditions) and the 65 side drop to conservatively envelope the effects of a corner drop.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.1-2 DSC Results - Load Combinations (2 Sheets)

Load Stress Category [ksi]

Service Combination Loads Components Pm(or Pm(or Level Pm Pm+Pb PL Number PL)+Pb+Q PL)+Pb+Q+Pe Stress Intensity 6.77 12.11 18.07 27.90 45.44 DSC Shell Allowable Stress 17.50 26.25 26.25 52.50 52.50 (Confinement)

Stress Ratio 0.39 0.46 0.69 0.53 0.87 DSC Shell Stress Intensity 4.99 6.87 7.46 11.61 31.00 (Non- Allowable Stress 17.50 26.25 26.25 52.50 52.50 Confinement) Stress Ratio 0.29 0.26 0.28 0.22 0.59 Stress Intensity 1.81 7.01 2.99 8.46 15.08 OTCP Allowable Stress 17.50 26.25 26.25 52.50 52.50 DW+IP Stress Ratio 0.10 0.27 0.11 0.16 0.29 9 A (20psi) Stress Intensity 1.96 7.12 3.62 10.96 17.30 ITCP Allowable Stress 17.50 26.25 26.25 52.50 52.50 Stress Ratio 0.11 0.27 0.14 0.21 0.33 Stress Intensity 1.10 2.71 1.91 5.61 20.15 OBCP Allowable Stress 17.50 26.25 26.25 52.50 52.50 Stress Ratio 0.06 0.10 0.07 0.11 0.38 Stress Intensity 2.87 4.72 5.23 8.20 24.42 IBCP Allowable Stress 17.50 26.25 26.25 52.50 52.50 Stress Ratio 0.16 0.18 0.20 0.16 0.47 Page A.3.9.1-9 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.1-2 DSC Results - Load Combinations (2 Sheets)

Load Stress Category[ksi]

Service Combination Loads Components Level Pm Pm+Pb PL Number Stress Intensity 22.10 29.10 34.00 DSC Shell Allowable Stress 44.38 57.06 57.06 (Confinement)

Stress Ratio 0.50 0.51 0.60 DSC Shell Stress Intensity 20.10 22.60 20.30 (Non- Allowable Stress 44.38 57.06 57.06 Confinement) Stress Ratio 0.45 0.40 0.36 Stress Intensity 7.13 13.00 14.30 OTCP Allowable Stress 44.38 57.06 57.06 DW+ Stress Ratio 0.16 0.23 0.25 10 D Seismic+

IP(20psi) Stress Intensity 5.53 11.20 9.27 ITCP Allowable Stress 44.38 57.06 57.06 Stress Ratio 0.12 0.20 0.16 Stress Intensity 19.80 26.70 5.60 OBCP Allowable Stress 44.38 57.06 57.06 Stress Ratio 0.45 0.47 0.10 Stress Intensity 11.10 16.10 18.60 IBCP Allowable Stress 44.38 57.06 57.06 Stress Ratio 0.25 0.28 0.33 Page A.3.9.1-10 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.1-3 DSC Weld Stress Results- Load Combinations Load Stress Service Weld Stress Allowable Stress Combination Loads Intensity Level Components Category Stress [ksi] Ratio Number [ksi]

PL 16.50 23.2 0.71 DSC-ITCP PL+Pb+Q+Pe 40.19 46.3 0.87 PL 11.57 23.2 0.50 9 A DW+IP (20psi) DSC-OTCP PL+Pb+Q+Pe 30.24 46.3 0.65 PL 5.46 23.2 0.24 DSC-OBCP PL+Pb+Q+Pe 25.77 46.3 0.56 DSC-ITCP PL 25.0 46.9 0.53 DW+

10 D Seismic + DSC-OTCP PL 38.8 46.9 0.83 IP (20psi)

DSC-OBCP PL 17.30 46.9 0.37 Page A.3.9.1-11 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.1-4 DSC-OTCP Maximum Radial Weld Stress (Sx) Results- Load Combinations Load Maximum Radial Stress Combination Service Level Loads

[ksi]

Number 9 A DW+IP (20psi) 0.14 DW+Seismic 10 D 4.22

+IP(20psi)

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.1-5 Controlling DSC Load Combination Results Summary Controlling Load Combination (1) Max.

Service Components / Welds Stress Number Description Level Ratio DSC Shell Containment 9 DW + IP + Thermal A 0.87 DSC Shell Non DW + Ram Retrieval+ IP +

5 A/B 0.85 Containment Thermal OTCP 8 DW + Accident P D 0.45 ITCP 8 DW + Accident P D 0.45 DW + Ram Retrieval + IP +

OBCP 5 A/B 0.78 Thermal DW + Ram Insert + IP +

IBCP 4 A/B 0.47 Thermal DW + Ram Retrieval + IP +

Grapple Support 5 A/B 0.92 Thermal DW + Ram Retrieval + IP +

Grapple Ring 5 A/B 0.81 Thermal DW + IP + max (HS_TOP, OTCP-DSC Shell Weld 10 D 0.83 HS_BOT)

ITCP-DSC Shell Weld 9 DW + IP A 0.87 DW + Ram Retrieval + IP +

OBCP-DSC Shell Weld 5 A/B 0.75 Thermal (1)

Note: See Table A.3.9.1-1 for the load combination description.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.1-1 DSC Supports and Axial Retainers Page A.3.9.1-14 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.1-2 DSC Dead Weight Equivalent Pressure Page A.3.9.1-15 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.1-3 DSC Boundary Conditions in HSM-MX Page A.3.9.1-16 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.1-4 Internals Seismic Equivalent Pressures with Internal Pressure, Load Case 2 Page A.3.9.1-17 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.2 EOS-37PTH AND EOS-89BTH BASKET STRUCTURAL ANALYSIS There is no change to the EOS-37PTH and EOS-89BTH Basket Structural evaluation documented in Sections 3.9.2 due to the addition of the NUHOMS MATRIX.

Page A.3.9.2-1 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.3 NUHOMS EOS SYSTEM ACCIDENT DROP EVALUATION There is no change to the EOS-37PTH DSC and EOS-89BTH DSC within the EOS-TC108 for drop evaluation documented in Sections 3.9.3 due to the addition of the NUHOMS MATRIX.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.3.9.4 HSM-MX STRUCTURAL ANALYSIS Table of Contents A.3.9.4 HSM-MX STRUCTURAL ANALYSIS.......................................................... A.3.9.4-1 A.3.9.4.1 General Description ........................................................................ A.3.9.4-1 A.3.9.4.2 Material Properties ......................................................................... A.3.9.4-1 A.3.9.4.3 Design Criteria ................................................................................ A.3.9.4-1 A.3.9.4.4 Load Cases ....................................................................................... A.3.9.4-2 A.3.9.4.5 Load Combination .......................................................................... A.3.9.4-2 A.3.9.4.6 Finite Element Models .................................................................... A.3.9.4-2 A.3.9.4.7 Normal Operation Structural Analysis ......................................... A.3.9.4-4 A.3.9.4.8 Off-Normal Operation Structural Analysis.................................. A.3.9.4-5 A.3.9.4.9 Accident Condition Structural Analysis ....................................... A.3.9.4-6 A.3.9.4.10 Structural Evaluation ................................................................... A.3.9.4-11 A.3.9.4.11 Conclusions .................................................................................... A.3.9.4-21 A.3.9.4.12 References ...................................................................................... A.3.9.4-22 Page A.3.9.4-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Tables Table A.3.9.4-1 Design Pressures for Tornado Wind Flowing from Front Wall to Rear Wall and Vice Versa............................................................... A.3.9.4-23 Table A.3.9.4-2 Design Pressures for Tornado Wind Flowing from Right Side to Left Side Wall and Vice Versa ....................................................... A.3.9.4-24 Table A.3.9.4-3 Spectral Acceleration Applicable to Different Components of HSM-MX for Seismic Analysis ...................................................... A.3.9.4-25 Table A.3.9.4-4 Load Cases for HSM-MX Concrete Components Evaluation ........ A.3.9.4-26 Table A.3.9.4-5 Load Combination for HSM-MX Concrete Components Evaluation ....................................................................................... A.3.9.4-27 Table A.3.9.4-6 Demand to Capacity Ratios for HSM-MX Longitudinal Reinforcement Areas ...................................................................... A.3.9.4-28 Page A.3.9.4-ii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Figures Figure A.3.9.4-1 HSM-MX (Back-to-Back) CAD Model ......................................... A.3.9.4-29 Figure A.3.9.4-2 HSM-MX (Back-to-Back) Meshed Model ..................................... A.3.9.4-30 Figure A.3.9.4-3 Temperature Distribution of HSM-MX for Normal Thermal Hot Condition......................................................................................... A.3.9.4-31 Figure A.3.9.4-4 Temperature Distribution of HSM-MXS for Blocked Vent Accident Thermal Condition........................................................... A.3.9.4-32 Figure A.3.9.4-5 HSM-MX Concrete Reinforcement Directions .............................. A.3.9.4-33 Figure A.3.9.4-6 Analytical Model of Heat Shield (a) Coupled Lower Side Heat Shield and Studs (b) Coupled Lower Top Heat Shield and Studs .. A.3.9.4-34 Figure A.3.9.4-7 Horizontal Target and 5% Spectral Match (Horizontal 1, Hector Mine Earthquake)............................................................................ A.3.9.4-35 Figure A.3.9.4-8 Baseline Corrected Acceleration, Velocity and Displacement Time Histories (Horizontal 1, Hector Mine Earthquake) ............... A.3.9.4-36 Figure A.3.9.4-9 Horizontal Target and 5% Spectral Match (Horizontal 2, Hector Mine Earthquake)............................................................................ A.3.9.4-37 Figure A.3.9.4-10 Baseline Corrected Acceleration, Velocity and Displacement Time Histories (Horizontal 2, Hector Mine Earthquake) ............... A.3.9.4-38 Figure A.3.9.4-11 Vertical Target and 5% Spectral Match (Vertical Up, Hector Mine Earthquake)............................................................................ A.3.9.4-39 Figure A.3.9.4-12 Baseline Corrected Acceleration, Velocity and Displacement Time Histories (Vertical Up, Hector Mine Earthquake) ................. A.3.9.4-40 Figure A.3.9.4-13 Lower Top Heat Shield Support Node ISRS due to Envelope of Four Earthquake-Based Motions Compatible with Enhanced RG1.60 Spectra, 4% Damping, X-Direction .................................. A.3.9.4-41 Figure A.3.9.4-14 Lower Top Heat Shield Support Node ISRS due to Envelope of Four Earthquake-Based Motions Compatible with Enhanced RG1.60 Spectra, 4% Damping, Y-Direction .................................. A.3.9.4-42 Figure A.3.9.4-15 Lower Top Heat Shield Support Node ISRS due to Envelope of Four Earthquake-Based Motions Compatible with Enhanced RG1.60 Spectra, 4% Damping, Z-Direction ................................... A.3.9.4-43 Page A.3.9.4-iii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.4 HSM-MX STRUCTURAL ANALYSIS The purpose of this appendix is to present the structural evaluation of the NUHOMS MATRIX (HSM-MX) due to all applied loads during storage and transfer operations.

A.3.9.4.1 General Description General description and operational features for the HSM-MX is provided in Appendix A.1. The HSM-MX is a freestanding, staggered reinforced concrete structure, designed to provide environmental protection and radiological shielding for the EOS-37PTH/EOS-89BTH DSC. The drawings of the HSM-MX, showing different components and overall dimensions, are provided in Appendix A.1.3 The HSM-MX is one of the three main components of the NUHOMS MATRIX System. The system consists of the dual purpose (Transportation/Storage) EOS-37PTH/EOS-89BTH DSC, the HSM-MX, and the onsite transfer cask (EOS-TC) with associated ancillary equipment.

The HSM-MX overpack system comprises the MATRIX Horizontal Storage Modules, the MATRIX retractable roller tray (MX-RRT), the MATRIX loading crane (MX-LC) and associated trailer interface for storing dry shielded canisters (DSCs).

The HSM-MX is a staggered, two-tiered, high density, high-heat rejection, storage overpack that provides a self-contained modular structure for storage of DSCs. The HSM-MX is constructed from reinforced concrete and structural steel. The thick concrete roof and walls of the HSM-MX provide substantial neutron and gamma shielding. The monolithic structure increases resistance to earthquakes and offers significant self-shielding. The MX-RRT delivers the DSC from the transfer cask to the HSM-MX and places it on the front and rear DSC supports.

The HSM-MX can be arranged in both single-row or back-to-back row arrays.

For thermal protection of the HSM-MX concrete, stainless steel heat shields are installed inside the HSM-MX. The primary function of the heat shields is to limit the temperature of the surrounding concrete walls. The heat shields guide the cooling airflow through the HSM-MX.

A.3.9.4.2 Material Properties The material properties used in the analysis and design of the HSM-MX and its components are discussed in detail in Chapter 8 and Appendix A.8.

A.3.9.4.3 Design Criteria No change to Section 3.9.4.3.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.4.4 Load Cases A summary of the design loads for HSM-MX concrete component evaluation is similar to Table 3.9.4-4 except the definition of normal handling (Ro) and off-normal handling (Ra) loads, and is provided in Table A.3.9.4-4 for information only. This table also presents the applicable codes and standards for specific load.

A.3.9.4.5 Load Combination The load combinations used in the structural analysis of the HSM-MX structure comply with the requirements of 10 CFR 72.122 [A.3.9.4-1] and ANSI 57.9-84

[A.3.9.4-8] and are provided in Table A.3.9.4-5.

A.3.9.4.6 Finite Element Models The structural analysis of HSM-MX storage modules arranged in a back-to-back row array provides a conservative estimate of the response of the HSM-MX under the postulated static and dynamic loads for any HSM-MX array configurations. The frame and shear wall action of the HSM-MX concrete components are considered to be the primary load carrying mechanism of the structural system. The analytical model is evaluated for normal operating, off-normal, and postulated accident loads acting on the HSM-MX.

A single Finite Element Model (FEM) is developed for the HSM-MX storage arranged in a back-to-back row array, where each row consists of three lower compartments and two upper compartments. This is a configuration with the minimum number of storage modules that an HSM-MX array can have. A back-to-back row array, instead of a single row array, is considered because the back wall shared by two rows is only 30 inch whereas, for a single row array, the thickness of the rear shield wall at the modules back end is 44 inch. Moreover, an array with additional storage modules would have a greater natural frequency in the transverse direction (that is, the direction of array expansion), resulting in a lower seismic loads. Therefore, the model based on a back-to-back row array with each row consisting of three lower compartments and two upper compartments provides a conservative estimate of the response of the HSM-MX structural elements under various static and dynamic loads.

The analysis results from ANSYS are post-processed using CivilFEM [A.3.9.4-18]

software. CivilFEM defines the shell elements at the mid-planes of the walls and slabs that are represented by the 3D solid elements in the ANSYS model. Forces and moments on the shell elements that are equivalent to the displacement results on solid elements are computed by CivilFEM. Then the results of the shell forces and moments are utilized to determine reinforcement areas.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.4.6.1 Finite Element Model to Evaluate HSM-MX Concrete Components for Mechanical Loads A three-dimensional (3D) finite element model (FEM) of the HSM-MX, including all the concrete components, is developed in the computer program ANSYS [A.3.9.4-14].

The eight-node brick element (ANSYS element type SOLID185) is used to model the concrete structure. Each node of the eight-node brick element has three translational degrees of freedom. A global element dimension of 4-inch is used in the model. As demonstrated in A.3.9.4.6, the model can accurately simulate the frame and shear wall action of the HSM-MX concrete components, which are the primary load-resisting mechanisms. The mass of the DSC is evenly distributed over the four supports using lumped mass elements (ANSYS element type MASS21). The mass of the door is included as lumped mass elements placed around the recessed door opening at the five embedment locations of the door. The mass of the vent cover is also included as lumped mass elements at the vent cover support locations on the roof. A plot of the CAD model and ANSYS FEM of the HSM-MX back-to-back array are shown in Figure A.3.9.4-1 and Figure A.3.9.4-2, respectively. The coordinate system for the model is shown in Figure A.3.9.4-2, where the origin is located at the bottom left corner on the front.

The model is assumed to neither uplift due to dead weight nor slide due to friction with the ISFSI pad. Therefore, the model is restrained vertically at all nodes on the bottom of the model, and also restrained laterally and axially at all nodes on the bottom of the model to prevent rigid body movement.

A.3.9.4.6.2 Finite Element Model of the HSM-MX Concrete Structure for Thermal Stress Analysis Thermal stress analyses of the HSM-MX were performed using a 3D FEM, which includes only the concrete components developed in Section A.3.9.4.6.1. The connections of the door to the HSM-MX concrete structure are designed so that free thermal growth is permitted in these members when the HSM-MX is subjected to thermal loads. Because of their free thermal growth, the doors do not induce thermal stresses in the concrete components of the HSM-MX. Therefore, the analytical model of the HSM-MX for thermal stress analysis of the concrete components does not include doors. The ANSYS models with temperature profile, which are used to perform thermal stress analysis of the concrete components for normal thermal hot and blocked vent accident thermal conditions, are shown in Figure A.3.9.4-3 and Figure A.3.9.4-4, respectively.

For thermal stress analysis, the FEM has Z-degrees of freedom restrained along the bottom front edge of the module (Z=0 and Y=0 in the ANSYS model), X-degrees of freedom restrained along the bottom left side edge of the module (X=0 and Y = 0 in the ANSYS model), and Y-degrees of freedom restrained at the base of the module (Y=0 in the ANSYS model).

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.4.6.3 Finite Element Model for Structural Analysis of Heat Shield Panels and supporting brackets for the heat shields The primary function of the heat shields is to limit the temperature of the surrounding concrete walls to acceptable values. The stainless steel heat shields are evaluated for their ability to sustain structural integrity after being subjected to two loads: a combination of 1g dead load due to its own weight, and a seismic load that is dependent upon its natural frequency as well as the in-structure response spectra (ISRS) at the supports.

The FEMs of the HSM-MX (single and back-to-back double) arrays developed in Section A.3.9.4.6.1 are used for the modal time-history analysis using ANSYS. In order to determine the appropriate seismic loading for the heat shields, ISRS are determined for the locations of the various heat shield attachments. The ISRS are determined by performing modal time history analysis of the entire HSM-MX structures. ANSYS is used to determine the natural vibration frequencies of the coupled panel-stud system. Shell elements (ANSYS element type SHELL63) are used to model the heat shield panels and support brackets and beam elements (ANSYS element type BEAM4) are used for the studs. The analytical models of the coupled lower side heat shield (LSHS) and Studs, and coupled lower top heat shield (LTHS) and studs are shown in Figure A.3.9.4-6. Similar models were used for the upper bottom heat shields (UBHS), upper side heat shield (USHS), and upper top heat shield (UTHS).

A.3.9.4.7 Normal Operation Structural Analysis This section describes the design basis normal operation events for the HSM-MX components and presents analyses that demonstrate the adequacy of the design safety features of the HSM-MX. The normal operating loads for which the HSM-MX components are designed include dead load, live load, normal handling loads, normal thermal loads, and wind load. The ANSYS FEM described in Section A.3.9.4.6.1 is used to evaluate concrete forces and moments due to these normal loads. The methodology used to evaluate the effects of these normal loads is addressed in the following paragraphs.

A.3.9.4.7.1 HSM-MX Dead Load (DL) Analysis Dead loads are applied to the analytical model by application of 1g acceleration in the vertical direction where g is the gravitational acceleration (386.4 in/sec2). The 5%

variation of dead load as indicated in ANSI/ANS 57.9 is not used because the heaviest design weight is used for analysis.

A.3.9.4.7.2 HSM-MX Live load (LL) Analysis Live load analysis is performed by applying 200 psf pressure on the roof. The DSC weight is also applied on the DSC supports as a live load.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.4.7.3 HSM-MX Normal Operational Handling Load (Ro) Analysis Normal operation assumes the canister is sliding over the MX-RRT due to a hydraulic ram force of up to 135,000 lbs (insertion) and 80,000 lbs (extraction) applied at the grapple ring and resisted by an axial load of 70,000 lb (insertion) and 40,000 lb (extraction) developing at each side of the MX-RRT supports. Here the total resisting axial load of 140,000 lbs is greater than the hydraulic ram force of 135,000 lbs. Only the insertion load is applied in the ANSYS FEM, since the extraction load is bounded by the insertion load. In addition, the DSC weight is applied to the MX-RRT support locations on both sides (4 points).

A.3.9.4.7.4 HSM-MX Normal Operating Thermal (To) Stress Analysis The normal operating thermal (To) loads on the HSM-MX include the effect of design basis heat load of up to 50 kW generated by the DSC, plus the effect of normal ambient temperature. To evaluate the effects of normal thermal loads on the HSM-MX, heat transfer analyses for a range of normal ambient temperatures (-20 °F and 100 °F) are performed with a DSC heat load of 50 kW. The normal thermal cold condition (-20 F) is bounded by the off-normal thermal cold condition (-40 F).

Therefore, the off-normal thermal cold condition is used in place of the normal thermal cold condition. The ambient condition that causes the maximum temperature and maximum gradients in the concrete components is used in the analysis. The normal thermal hot condition is the governing case for this load case. The HSM-MX thermal stress analysis was performed using thermal profiles and maximum temperatures that bound those reported in Section A.4.5. The ANSYS FEM described in Section A.3.9.4.6.2 is used for the normal thermal load analysis.

A.3.9.4.7.5 HSM-MX Design Basis Wind Load (W) Analysis The DSCs inside the HSM-MX are not affected by wind load. The concrete structure forces and moments due to the design basis wind load (W) are bounded by the result of tornado generated wind load discussed in Section A.3.9.4.9.1. Therefore, no separate analysis is performed for this case.

A.3.9.4.8 Off-Normal Operation Structural Analysis This section describes the design basis off-normal events for the HSM-MX components and presents analyses that demonstrate the adequacy of the design safety features of the HSM-MX.

The off-normal operating loads for which the HSM-MX components are designed include off-normal handling load and off-normal thermal load.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 For an operating NUHOMS MATRIX System, off-normal events could occur during fuel loading, TC handling, canister transfer, trailer towing, and other operational events. Two credible off-normal events bound the range of off-normal conditions for the HSM-MX. The limiting off-normal events as defined above are defined as a jammed DSC during loading or unloading from the HSM-MX and the extreme ambient temperatures of -40 °F (winter) and +117 °F (summer). These events bound the range of expected off-normal structural loads and off-normal temperatures acting on the HSM-MX. The ANSYS FEM described in Section A.3.9.4.6.1 is used to evaluate concrete forces and moments due to these loads.

A.3.9.4.8.1 HSM-MX Off-Normal Handling Loads (Ra) Analysis This load case assumes that the EOS-TC is not accurately aligned with respect to the HSM-MX resulting in binding of the DSC during a transfer operation causing the hydraulic pressure in the ram to increase. The ram force is limited to a maximum load of 135,000 lbs during insertion, as well as during retrieval. Therefore, for the DSC, the off-normal jammed canister load (Ra) is defined as an axial load of 135,000 lbs on one side of MX-RRT supports. In addition, the DSC weight is applied to MX-RRT support locations of the loaded MX-RRT rail (2 points).

A.3.9.4.8.2 HSM-MX Off-Normal Thermal Loads Analysis This load case is the same as the normal thermal load, but with an ambient temperature range from -40 F to 117 F. The temperature distributions for the extreme ambient conditions are considered for the concrete component evaluation.

The concrete forces and moments due to this load case are bounded by the results of the accident blocked vent condition discussed in Section A.3.9.4.9.4. Therefore, no separate analysis is performed for this case.

A.3.9.4.9 Accident Condition Structural Analysis The design basis accident events specified by ANSI/ANS 57.9-1984, and other credible accidents postulated to affect the normal safe operation of the HSM-MX are addressed in this section.

Each accident condition is analyzed to demonstrate that the requirements of 10 CFR 72.122 are met and that adequate safety margins exist for the HSM-MX design. The resulting accident condition stresses, forces and moments in the HSM-MX components are evaluated and compared with the applicable code limits. The postulated accident conditions addressed in this section include:

Tornado winds and tornado generated missiles (Wt, Wm)

Design basis earthquake (E)

Design basis flood (FL)

Blocked Vent Accident Thermal (Ta)

The ANSYS FEM described in Section A.3.9.4.6.1 is used to evaluate concrete forces and moments due to these loads.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.4.9.1 Tornado Winds/Tornado Missile Load (Wt, Wm) Analysis The most severe tornado generated wind and missile loads selected for analysis are specified by U.S. NRC (NRC) Regulatory Guide 1.76 [A.3.9.4-4] and NUREG-0800

[A.3.9.4-5]. The extreme design basis wind loads are less severe than tornado generated wind loads and, therefore, do not need to be addressed.

The tornado wind intensities used for the HSM-MX analysis are obtained from NRC Regulatory Guide 1.76, Rev. 0 [A.3.9.4-4], which bound the design basis requirements. Region I intensities are utilized since they result in the most severe loading parameters. For this region, the maximum wind speed is 360 mph, the rotational speed is 290 mph, and the maximum translational speed is 70 mph. The radius of the maximum rotational speed is 150 ft, the pressure drop across the tornado is 3 psi and the rate of pressure drop is 2 psi per second [A.3.9.4-4].

The maximum wind speed used of 360 mph provides substantial conservatism relative to the maximum wind speed of 230 mph prescribed in current regulatory guidance in NRC Regulatory Guide 1.76 Revision 1 [A.3.9.4-17]. For the purposes of the structural evaluation as described in Appendix A.3, as well as the accident evaluation as described in Appendix A.12 the design basis tornado (DBT) refers to the bounding criteria from Regulatory Guide 1.76, Rev. 0 used in the analysis.

Tornado loads are generated for three separate loading phenomena:

Pressure or suction forces created by drag as air impinges and flows past the HSM-MX. These pressure or suction forces are due to tornado-generated wind with maximum wind speed of 360 mph.

Pressure or suction forces created by drag due to tornado-generated pressure drop or differential pressure load of 3 psi.

Impact, penetration and spalling forces created by tornado-generated missiles impinging on the HSM-MX.

The determination of impact forces created by tornado missiles for the HSM-MX is consistent with that presented in Section 2.3.1.2. The four types of missiles listed below envelope the missile spectrum of NUREG-0800, Revision 2, Section 3.5.1.4

[A.3.9.4-5]. These missiles also bound the design basis missile spectrum of NRC Regulatory Guide 1.76, Revision 1 [A.3.9.4-17] and NUREG 0800, Revision 3, Section 3.5.1.4 [A.3.9.4-6]. Evaluation of the effects of small diameter spherical missiles (artillery) is not required because there are no openings in the HSM-MX leading directly to the DSC through which such missiles could pass.

1. Utility wooden pole, 13.5 diameter, 35 long, Weight = 1124 lbs, Impact velocity

= 180 fps.

2. Armor piercing artillery shell 8 diameter, Weight = 276 lbs, Impact velocity =

185 fps.

3. Steel pipe, 12.75 diameter, Schedule 40, 15 ft long, Weight = 750 lbs, Impact velocity = 154 fps.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20

4. Automobile traveling through the air not more than 25 ft above the ground and having contact area of 20 sq. ft, Weight = 4000 lbs, Impact Horizontal Velocity =

195 fps.

Stability and stress analyses are performed to determine the response of the HSM-MX to tornado wind pressure loads. The stability analyses are discussed in detail in Appendix A.3.9.7. The stress analyses are performed using the ANSYS FEM of the HSM-MX to determine design forces and moments. These conservative analyses envelope the effects of wind pressures on the HSM-MX in other array configurations.

Thus, the requirements of 10 CFR 72.122 are met.

The HSM-MX is qualified for maximum design basis tornado (DBT) generated design wind loads of 238 psf and 167 psf on the windward and leeward HSM-MX walls (See Table A.3.9.4-1 and Table A.3.9.4-2), respectively, and a pressure drop of 3 psi.

An HSM-MX array is protected by end side walls, shield walls, or an adjacent module.

For an HSM-MX array, the module on the windward end of the array has either an end side wall or an end shield wall to protect the module from tornado missile impacts.

The end walls are also subjected to the 238 psf windward pressure load. The 167 psf suction load is applicable to the end side wall on the opposite end module in the array.

A suction of 355 psf is also applied to the roof of each HSM-MX in the array.

For the stress analyses, the DBT wind pressures are applied to the HSM-MX as uniformly distributed loads. The bending moments and shear forces at critical locations in the HSM-MX concrete components are calculated by performing an analysis using the ANSYS analytical model of the HSM-MX as described in Section A.3.9.4.6. The wind and tornado loads are identified as load combination C2 and C5 as provided in Table A.3.9.4-5. The demand to capacity ratios in terms of reinforcement areas for the bounding load combinations are presented in Table A.3.9.4-6 for each of the HSM-MX components.

Conservatively, the design basis extreme wind pressure loads are assumed to be equal to those calculated for the DBT (based on 360 mph wind speed) in the formulation of HSM-MX load combination results.

In addition, the adequacy of the HSM-MX to resist tornado missile loads is checked using the modified National Defense Research Committee (NDRC) empirical formulae [A.3.9.4-10] for local damage evaluation, and response chart solution method [A.3.9.4-13] for global response. These evaluations are described in Section A.3.9.4.10.5.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.4.9.2 Earthquake (Seismic) Load (E) Analysis The design basis seismic load used for analysis of the HSM-MX components is as discussed in Section A.2.3.4. Based on NRC Regulatory Guide 1.61 [A.3.9.4-3], a damping value of 4% is used for seismic analysis of steel structural components and a damping value of 7% is used for seismic analysis of concrete components of the HSM-MX. An evaluation of the frequency content of the loaded HSM-MX is performed to determine the amplified accelerations associated with the design basis seismic response spectra for the HSM-MX. The results of the frequency analysis of the HSM-MX structure (which includes a simplified model of the DSC) yield a lowest frequency of 23.94 Hz in the transverse direction and 24.08 Hz in the longitudinal direction. The lowest vertical frequency exceeds 45 Hz; therefore, the spectral acceleration is not amplified in the vertical direction. Thus, based on the enhanced Regulatory Guide 1.60 response spectra amplifications, the corresponding seismic accelerations used for the design of the HSM-MX are 1.33g and 1.33g in the transverse and longitudinal directions, respectively, and 0.800g in the vertical direction. The resulting amplified accelerations are given in Table A.3.9.4-3.

An equivalent static analysis of the HSM-MX is performed using the ANSYS FEM described in Section A.3.9.4.6.1 by applying the amplified seismic accelerations load.

The dominant frequencies are lower for the double row array in the X and Y directions, whereas the single row array has a lower frequency in the Z direction.

Therefore, the spectral accelerations to be used in seismic analysis are taken from the double row array model for the X and Y directions, and from the single row array model for the Z direction.

The responses for each orthogonal direction are combined using the square root of the sum of the squares (SRSS) method. The resulting moments and forces due to the combined seismic load are included in the HSM-MX load combination results.

For sites having a higher zero period acceleration than analyzed, the reinforcement requirement may need to be reviewed, and additional rebar may be added for such sites.

The stability evaluation of the HSM-MX due to seismic load is discussed in Appendix A.3.9.7.

Seismic analysis of the HSM-MX heat shields consists of a modal time-history analysis of the HSM-MX using the seismic acceleration load corresponding to the ISRS with +/-15% peak-broadening and the frequency response of each type of heat shield. The ground motion time histories used in the modal time-history analysis of the HSM-MX are based on four earthquakes, Hector Mine, Chi-Chi, Denali, Mianzhuqingping.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The time histories are compatible with the enhanced NRC Regulatory Guide 1.60

[A.3.9.4-2] response spectra. The acceleration, velocity, and displacement time histories and corresponding spectra in the two horizontal and vertical directions, all with 1.0g zero period acceleration (ZPA), are shown for the ground motion based on the Hector Mine earthquake in Figure A.3.9.4-7 through Figure A.3.9.4-12 for information only. The time histories are scaled down in the modal time-history analyses because their response spectra are anchored at 1.0g ZPA whereas the seismic criteria for the HSM-MX are based on 0.85g ZPA in the horizontal directions and 0.80g ZPA in the vertical direction. The envelops of the ISRS of heat shield support nodes due to the four ground motions are shown in Figure A.3.9.4-13 through Figure A.3.9.4-15 for lower top heat shield (LTHS) only.

A.3.9.4.9.3 Flood Load (FL) Analysis Since the source of flooding is site specific, the exact source, or quantity of flood water, should be established by the licensee. However, for this generic evaluation of the HSM-MX, bounding flooding conditions are specified that envelope those that are postulated for most plant sites. As described in Section 2.3.3, the design basis flooding load is specified as a 50-foot static head of water and a maximum flow velocity of 15 feet per second. Each licensee should confirm that this represents a bounding design basis for their specific ISFSI site.

Since the HSM-MX is open to the atmosphere, static differential pressure due to flooding is not a design load.

The maximum drag pressure, D, acting on the HSM-MX due to a 15 fps flood water velocity is calculated as follows:

CD w V2 D = [A.3.9.4-15]

2g Where:

V = 15 fps, Flood water velocity CD = 2.0, Drag coefficient for flat plate w = 62.4 lb/ft3, Flood water density g = 32.2 ft/sec2, Acceleration due to gravity D = Drag pressure (psf)

The resulting flood induced drag pressure is: D = 436 psf.

The following flood load cases are considered to account for different flow direction:

Case 1: Flood water flowing longitudinally from the front row to the back row of the module or vice versa.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Case 2: Flood water flowing transversely from the right side wall to the left side wall of the module or vice versa.

The ANSYS FEM described in Section A.3.9.4.6.1 is used for the structural evaluation. The results for the flood load case are obtained by enveloping results from the above load cases.

The stability evaluation of the HSM-MX due to flood load is discussed in Appendix A.3.9.7.

A.3.9.4.9.4 Accident Blocked Vent Thermal (Ta) Stress Analysis The postulated accident thermal event occurs due to blockage of the air inlet and outlet vents under off-normal ambient temperatures range from -40 °F to 117 °F. The HSM-MX thermal stress analysis was performed using the thermal profiles and maximum temperatures reported in Section A.4.5.

The ANSYS FEM described in Section A.3.9.4.6.2 is used for the structural analysis for the accident blocked vent condition.

A.3.9.4.10 Structural Evaluation The load categories associated with normal operating conditions, off-normal conditions and postulated accident conditions are described previously. The load combination results and design strengths of HSM-MX components are presented in this section.

A.3.9.4.10.1 HSM-MX Concrete Components To determine the required strength (internal axial forces, shear forces, and bending moments) for each HSM-MX concrete component, linear elastic finite element analyses are performed for the normal, off-normal, and accident loads using the analytical models described in Sections A.3.9.4.6.1 and A.3.9.4.6.2 for mechanical and thermal loads, respectively.

The concrete design loads are multiplied by load factors and combined to simulate the most adverse load conditions. The load combinations listed in Table A.3.9.4-5 are used to evaluate the concrete components. The demand to capacity ratios (in terms of reinforcement areas) for the bounding load combinations are presented in Table A.3.9.4-6 for each HSM-MX component. The reinforcement directions are shown in Figure A.3.9.4-5. The thermal stresses of HSM-MX concrete components used in the load combination results are based on thermal results that bound those reported in Section A.4.5.

Page A.3.9.4-11 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The required longitudinal reinforcement areas for the critical sections of concrete are calculated in accordance with the requirements of ANSI 57.9 [A.3.9.4-8] and ACI 349-06 [A.3.9.4-9], including the strength reduction factors defined in ACI 349-06, Section 9.3. The longitudinal reinforcement areas provided for the HSM-MX concrete components exceed the required reinforcement areas as shown in Table A.3.9.4-6.

A.3.9.4.10.2 HSM-MX Shield Door The shield door is free to grow in the radial direction when subjected to thermal loads.

Therefore, there are no stresses in the door due to thermal growth. The dead weight, differential pressure, flood and seismic loads cause insignificant stresses in the door compared to stresses due to missile impact load. Therefore, the door is evaluated only for the missile impact load.

The minimum thickness of a concrete component to prevent perforation and scabbing are 18.5 inches and 27.7 inches, respectively. Thus, the 28-inch thick door is adequate to protect from local damage due to missile impact. The computed maximum ductility ratio for the door is less than 2, which satisfies the ductility requirement if compared against the allowable ductility ratio of 10 as per ACI 349-06 [A.3.9.4-9]. Therefore, the concrete door meets the ductility requirement and is adequate to protect from the global effect of missile impact.

A.3.9.4.10.3 HSM-MX Heat Shield The heat shield panels are connected by bolts and threaded studs to the support brackets and surrounding concrete walls. The HSM-MX heat shield consists of different variations such as lower cavity side heat shield (LSHS), lower cavity top heat shield (LTHS), upper cavity bottom heat shield (UBHS), upper cavity side heat shield (USHS) and upper cavity top heat shield (UTHS).

The heat shield panels consists of 12 gauge 0.1054-inch thick stainless steel.

The maximum interaction ratio for the combined axial and bending stress for all bolts is 0.98, which is less than 1.0, in the UBHS and maximum bending stress in the panel is 30.0 ksi, which is less than the allowable stress of 32.2 ksi.

The maximum temperature used in the stress analysis of the heat shields bounds the maximum temperatures reported in Section A.4.5. Expansion due to off-normal and accident condition for all heat shields will not be restrained by the supporting elements.

Page A.3.9.4-12 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.4.10.4 HSM-MX DSC Axial Retainer The DSC axial retainer consists of a 3.5 in x 3.5 in solid steel square rod. The axial retainer slides horizontally through the HSM-MX door and stops the forward motion of the DSC towards the door. The anchor plate of the axial retainer (2 1/2 in. thick, in the middle and 2 in. thick near the edge 6 in. x 15 in. plate), which is bolted to the door, supports the axial motion of the retainer and transfers the DSC seismic load to the door. The motion towards the back wall is controlled by the rear stop plate.

The calculated compressive strength of the axial retainer rod is 280.3 kips which is greater than the equivalent force of 270.5 kips, due to seismic load. The maximum seismically induced shear load in the anchor plate is 135.3 kips. The allowable shear strength of the anchor plate is 498.6 kips. The bounding seismically induced moment in the anchor plate is 507.2 in-kips. The allowable flexural strength of the anchor plate at that location is 714.0 in-kips. Hence, the DSC axial retainer design is adequate to perform its intended function.

A.3.9.4.10.5 Evaluation of Concrete Components for Missile Loading Missile impact effects are assessed in terms of local damage and overall structural response. Local damage that occurs in the immediate vicinity of the impact area is assessed in terms of penetration, perforation, spalling and scabbing. Evaluation of local effects is essential to ensure that protected items (the DSC and fuel) would not be damaged by a missile perforating a protective barrier, or by secondary missiles such as scabbing particles. Evaluation of overall structural response is essential to ensure that protected items are not damaged or functionally impaired by deformation or collapse of the impacted structure.

The tornado-generated missiles are conservatively assumed to strike normal to the surface with the long axis of the missile parallel to the line of flight to maximize the local effects. Plastic deformation to absorb the energy input by the tornado-generated missile load is desirable and acceptable, provided that the overall integrity of the structure is not impaired. Due to complex physical process associated with missile impact effects, the HSM-MX structure is primarily evaluated conservatively by application of empirical formulae.

A.3.9.4.10.5.1 Local Damage Evaluation Local missile impact effects consist of (a) missile penetration into the target, (b) missile perforation through the target, and (c) spalling and scabbing of the target. This also includes punching shear in the region of the target. Per F.7.2.3 of ACI 349-06

[A.3.9.4-9], if the concrete thickness is at least 20% greater than that required to prevent perforation, the punching shear requirement of the code need not be checked.

The following enveloping missiles are considered for local damage:

Utility wooden pole Armor piercing artillery shell Page A.3.9.4-13 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 12-inch diameter schedule 40 steel pipe Large deformable missiles such as automobiles are incapable of producing significant local damage. Concrete thickness satisfying the global structural response requirements including punching shear is considered to preclude unacceptable local damage. Therefore, the local effects from an automobile are evaluated using punching shear criteria of ACI 349-06 [A.3.9.4-9]

The following empirical formulae are used to determine the local damage effects on reinforced concrete target:

A. Modified NDRC formulas for penetration depth [A.3.9.4-10]:

1.8 vo x 4 KNWd , for x/d 2.0 1000 d vo 1.8 x KNW d , for x/d > 2.0 1000 d Where, x = Missile penetration depth, inches 180 K= concrete penetrability factor =

f c' N = projectile shape factor

= 0.72 flat nosed

= 0.84 blunt nosed

= 1.0 bullet nosed (spherical end)

= 1.14 very sharp nose W = weight of missile, lb o = striking velocity of missile, fps d = effective projectile diameter, inches.

for a solid cylinder, d = diameter of projectile and for a non-solid cylinder, d = (4Ac/)1/2 Ac = projectile impact area, in2 B. Modified NDRC formula for perforation thickness [A.3.9.4-10]:

2 e x x 3.19 0.718 , for x/d 1.35 d d d e x 1.32 1.24 , for 1.35 x/d 13.5 d d Page A.3.9.4-14 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Where, e = perforation thickness, in.

In order to provide an adequate margin of safety the design thickness td = 1.2e

[A.3.9.4-9]

C. Modified NDRC formula for scabbing thickness [A.3.9.4-10]:

2 s x x 7.91 5.06 , for x/d 0.65 d d d s x 2.12 1.36 , for 0.65 x/d 11.75 d d Where, s = scabbing thickness, in.

In order to provide an adequate margin of safety the design thickness td = 1.2s

[A.3.9.4-9]

The concrete targets of the HSM-MX that may be subjected to local damage due to missile impact are:

24-inch thick roof panel 44-inch thick roof side wall 39-inch thick (minimum) front wall 36-inch thick end shield wall 36-inch thick end shield wall with 11-inch thick (minimum) side wall (upper compartment) 44-inch thick end wall (lower compartment) 82-inch thick end wall (upper compartment) 44-inch thick rear wall (for the case of single row array)

The minimum thickness of concrete target components listed above is 36 inches and 24 inches for horizontal and vertical missiles impacts, respectively. So, the required perforation thickness and required scabbing thickness are compared against 36 inches and 24 inches for horizontal and vertical missiles impacts, respectively, to ensure the adequacy of design.

Page A.3.9.4-15 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Local Impact Effects of Utility Wooden Pole Missile Per section 6.4.1.2.5 of [A.3.9.4-10], utility wooden pole missiles do not have sufficient strength to penetrate a concrete target and that the scabbing thickness required for wood missiles is substantially less than that required for a steel missile with the same mass and velocity. Practically, wooden pole missiles do not appear to be capable of causing local damage to the 12-inch or thicker walls (also see Section 2.1.1 of [A.3.9.4-13]). Since none of the concrete targets are less than 12 inches thick, the postulated wood missiles do not cause any local damage to the HSM-MX concrete component.

Local Impact Effects of Armor Piercing Artillery Shell Missile The penetration depth for this missile is calculated using the NDRC Formula as given in Section A.3.9.4.10.5.1 (a) and the parameters used in the formula are as listed below:

d = 8.0 in. effective diameter of missile W = 276 lb weight of missile vo = 185 fps striking velocity of missile fc = 5000 psi concrete compressive strength K = 180/5000 = 2.55 concrete penetrability factor N = 0.84 projectile shape factor (blunt nosed)

Penetration depth, x = 4.6 in. for x/d (= 0.58) 2.0 Perforation thickness, e = 12.9 in. for x/d (= 0.58) 1.35 Required perforation thickness = 1.2*12.9 = 15.5 in. < 36 in.

Scabbing thickness, s = 23.1 in. for x/d (= 0.58) 0.65 Required scabbing thickness = 1.2*23.1 = 27.7 in. 36 in.

Similarly, for vertical impact:

Required perforation thickness = 11.2 in. < 24 in Required scabbing thickness = 22.7 in. < 24 in Therefore, penetration and perforation of the concrete components of the HSM-MX do not occur due to this missile impact.

Local Impact Effects of 12-Inch Diameter Schedule 40 Steel Pipe Missile The penetration depth for this missile is calculated using the NDRC Formula as given in Section A.3.9.4.10.5.1 and the parameters used in the formula are as listed below:

= 12.75 in. outer diameter of 12-inch dia. schedule 40 steel pipe.

Ac = 15.74 in2 missile impact area (cross sectional area of steel)

Page A.3.9.4-16 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 d = (4*15.74/)1/2 = 4.5 in. effective diameter of missile W = 750 lb weight of missile vo = 154 fps striking velocity of missile fc = 5000 psi concrete compressive strength K = 180/5000 = 2.55 concrete penetrability factor N = 0.72 projectile shape factor (flat nosed)

Penetration depth, x = 7.6 in. for x/d (= 1.69) 2.0 Perforation thickness, e = 15.4 in. for 1.35 x/d (= 1.69) 13.5 Required perforation thickness = 1.2*15.4 = 18.5 in. < 36 in.

Scabbing thickness, s = 19.9 in. for 0.65 x/d (= 1.69) 11.75 Required scabbing thickness = 1 .2*19.9 = 23.9 in. < 36 in.

Similarly, for vertical impact:

Required perforation thickness = 14.8 in. < 24 in Required scabbing thickness = 20 in. < 24 in Therefore, penetration and perforation of the concrete components of the HSM-MX do not occur due to this missile impact.

A.3.9.4.10.5.2 Global Structural Response When a missile strikes a structure, large forces develop at the missile-structure interface, which decelerate the missile and accelerate the structure. The response of the structure depends on the dynamic properties of the structure and the time dependent nature of the applied loading (interface force-time function). The force-time function is, in turn, dependent on the type of impact (elastic or plastic) and the nature and extent of local damage.

In an elastic impact, the missile and the structure deform elastically, remain in contact for a short period of time (duration of impact), and subsequently disengage due to the action of elastic interface restoring forces.

In a plastic impact, the missile or the structure (or both) may sustain permanent deformation or damage (local damage). Elastic restoring forces are small, and the missile and the structure tend to remain in contact after impact. Plastic impact is much more common than elastic impact, which is rarely encountered. Test data have indicated that the impact from all postulated tornado-generated missiles can be characterized as a plastic impact.

Page A.3.9.4-17 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 If the interface forcing function can be defined or conservatively idealized, the structure can be modeled mathematically, and conventional analytical or numerical techniques can be used to predict structural response. If the interface forcing function cannot be defined, the same mathematical model of the structure can be used to determine structural response by application of conservation of momentum and energy balance techniques with due consideration for type of impact (elastic or plastic).

In either case, in lieu of a more rigorous analysis, a conservative estimate of structural response can be obtained by first determining the response of the impacted structural element, and then applying its reaction forces to the structure. The predicted structural response enables assessment of structural design adequacy in terms of strain energy capacity, deformation limits, stability and structural integrity.

The overall structural response of each component as a whole (global response) is determined by single degree of freedom analysis using response charts solution method of [A.3.9.4-13].

The following enveloping missiles are considered for global structural response:

Utility wooden pole Armor piercing artillery shell 12-inch diameter schedule 40 steel pipe Automobile missile The peak interface force and impact duration for each missile are calculated as follows:

A. Utility Wooden Pole Missile For wooden missile, the interface forcing function is a rectangular pulse having a force magnitude of F and duration ti, per Section 2.3.1 of [A.3.9.4-13]

F = PA ti = Mm c/F Where, F = interface force (lb)

P = interface pressure (psi) = 2500 psi for wood missiles [A.3.9.4-13]

A = cross sectional area of the missile (in2) =

• 13.52/4 = 143.1 in2 ti = impact duration (sec)

Wm = weight of missile (lb) = 1124 lb Mm = missile mass (lb-sec2/ft) = Wm/g = 1124 lb /32.2 ft/sec2 = 34.9 lb-sec2/ft c = change in velocity during impact (conservatively = s) (fps) = 180 fps Page A.3.9.4-18 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Therefore, F = 358 kip and ti = 0.0175 sec For the missile with vertical velocity, F is the same and ti =0.0117 sec B. Armor Piercing Artillery Shell For solid steel missile, the concrete is a soft target per section 6.4.2 of

[A.3.9.4-10] with a penetration depth of 4.6 in. The interface forcing function is a rectangular pulse per Section 6.4.2.1.1 of [A.3.9.4-10].

F = WmV02/2gX ti = 2X/V0 Where, F = interface force (lb) ti = impact duration (sec)

Wm = missile weight (lb) = 276 lb V0 = initial velocity of the missile (fps) = 185 fps X = penetration depth = 4.6 in.

Therefore, F = 383 kip and ti = 0.00414 sec For the missile with vertical velocity, F =170 kip and ti =0.00622 sec C. 12-Inch Diameter Schedule 40 Steel Pipe For steel pipe missile, the interface forcing function is a triangular pulse per Section 2.3.2 of [A.3.9.4-13].

ti = 400Mm /PA F = (2Mms)/ti Where, F = peak interface force (lb)

P = collapse stress of pipe (psi) = 60000 psi A = cross sectional metal area of the missile (in2) = 15.74 in2 ti = impact duration (sec)

Page A.3.9.4-19 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Wm = weight of missile (lb) = 750 lb Mm = missile mass (lb-sec2/ft) = Wm/g = 750 lb /32.2 ft/sec2 = 23.29 lb-sec2/ft s = striking velocity of missile = 154 fps Therefore, F = 728 kip and ti = 0.00986 sec For the missile with vertical velocity Fpeak = 485 kip D. Automobile Missile For automobile missile, the interface forcing function per 2.3.3 of [A.3.9.4-13] is as follows:

Ft = 0.625 c W sin(20t) 0 < t 0.0785 sec Ft = 0 t > 0.0785 sec Where, Ft = force as a function of time (lb)

W = weight of automobile (lb) = 4000 lb c = change in velocity during impact (conservatively = vs) (fps) = 195 fps Therefore, F = 488 kip and ti = 0.0785 sec For the missile with vertical velocity, Fpeak =325 kip The lower compartment module left sidewall, top left sidewall, right shield wall, front wall, rear wall, roof and roof sidewall of the HSM-MX are evaluated for global response, since these components may interface with missile loading. The lower compartment module left side wall, upper compartment module left side wall and rear wall are idealized as a simply supported plate. The roof is idealized as a plate clamped to three sides and free at the other side adjacent to vent opening. The roof sidewall is idealized as a plate clamped to three sides and free at the other side facing the top.

The yield resistance and fundamental period of vibration of concrete components are then determined based on the assumed idealized boundary condition using the equations given in Section 4.4 of [A.3.9.4-13]. For the right shield wall and front wall, ANSYS finite element models are used to determine the yield resistance and fundamental period of vibration. The calculated value of yield resistance, Ry, and fundamental period of vibration, Tn, for different concrete components are tabulated below.

Page A.3.9.4-20 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Component Ry (kip) Tn (sec)

Lower Compartment 1659 0.0048 Module Left Side Wall Upper Compartment Module 3255 0.0025 Left Side Wall Right Shield Wall 359.5 0.016 Front Wall 961.1 0.0079 Rear Wall 1659 0.0030 Roof 453.8 0.0040 Roof Side Wall 1659 0.0015 In the response chart solution method, the structural response is determined by entering the chart with calculated values of CT and CR to determine the ductility ratio,

, which is compared against the allowable ductility ratio as given in Appendix F of ACI 349-06 [A.3.9.4-9]. The dimensionless ratios, CT and CR, are defined as follows:

The maximum value of ductility ratio of all seven components is found to be less than the allowable ductility ratio per ACI 349-06 [A.3.9.4-9], which is 10 if flexure controls the design and 1.3 if shear controls the design. Hence, the global response of HSM-MX is within deformation limit meeting the ductility requirement.

Each component is also evaluated for punching shear capacity with interfacing utility wooden pole missile and automobile missile. All the components have punching shear capacity greater than the peak missile interface force.

A.3.9.4.11 Conclusions The load categories associated with normal operating conditions, off-normal conditions and postulated accident conditions are described and analyzed in previous sections. The load combination results for HSM-MX components important-to-safety are also presented. Comparison of the results with the corresponding design capacity shows that the design strength of the HSM-MX is greater than the strength required for the most critical load combination.

Page A.3.9.4-21 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.4.12 References A.3.9.4-1 Code of Federal Regulation Title 10, Part 72 (10CFR Part 72), Licensing Requirements for the Independent Storage of Spent Nuclear Fuel, High-Level Radioactive Waste, and Reactor-Related Greater than Class C Waste.

A.3.9.4-2 U.S. Nuclear Regulatory Commission, Regulatory Guide 1.60, Design Response Spectra for Seismic Design of Nuclear Power Plants, Revision 1, 1973.

A.3.9.4-3 U.S. Nuclear Regulatory Commission, Regulatory Guide 1.61, Damping Values for Seismic Design of Nuclear Power Plants, Revision 1, March 2007.

A.3.9.4-4 U.S. Nuclear Regulatory Commission, Regulatory Guide 1.76, Design Basis Tornado for Nuclear Power Plants, Revision 0, April 1974.

A.3.9.4-5 NUREG-0800, Standard Review Plan, Section 3.5.1.4, Missiles Generated by Natural Phenomena, Revision 2, July 1981.

A.3.9.4-6 NUREG-0800, Standard Review Plan, Section 3.3.1, Wind Loading, Section 3.3.2 Tornado Loads, and Section 3.5.1.4 Missiles Generated by Tornado and Extreme Winds, Revision 3, March 2007.

A.3.9.4-7 Not used.

A.3.9.4-8 ANSI/ANS 57.9-1984, Design Criteria for an Independent Spent Fuel Storage Installation (Dry Storage Type), American National Standards Institute, American Nuclear Society.

A.3.9.4-9 ACI 349-06, Code Requirements for Nuclear Safety Related Concrete Structures, American Concrete Institute.

A.3.9.4-10 American Society of Civil Engineers, Structural Analysis and Design of Nuclear Plant Facilities, ASCE Publication No. 58.

A.3.9.4-11 Not used.

A.3.9.4-12 American Society of Civil Engineers, Minimum Design Loads for Buildings and Other Structures, ASCE 7-10 (formerly ANSI A58.1).

A.3.9.4-13 Bechtel Corporation, Design Guide Number C-2.45 for Design of Structures for Tornado Missile Impact, Rev. 0, April 1982.

A.3.9.4-14 ANSYS Computer Code and Users Manual, Release 17.1 A.3.9.4-15 Binder, Raymond C., Fluid Mechanics, 3rd Edition, Prentice-Hall, Inc, 1973.

A.3.9.4-16 AREVA Inc., Updated Final Safety Analysis Report For The Standardized Advanced NUHOMS Horizontal Modular Storage System For Irradiated Nuclear Fuel, Revision 6, US NRC Docket Number 72-1029, August 2014.

A.3.9.4-17 U.S. Nuclear Regulatory Commission, Regulatory Guide 1.76, Design Basis Tornado for Nuclear Power Plants, Revision 1, March 2007.

A.3.9.4-18 CivilFEM Documentation, Release 17.1, SP1.

Page A.3.9.4-22 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.4-1 Design Pressures for Tornado Wind Flowing from Front Wall to Rear Wall and Vice Versa Max. Design Internal Pressure, Velocity External Pressure qv*(G*Cp-Pressure, qv Pressure Coefficient, GCpi)

Component (psf) Coefficient, Cp (GCpi) (psf)

Windward (Front Row Front Wall) 0.80 238 (1)

Leeward (Back Row Front Wall) -0.47 -160 Side (Right Side Wall) 276 -0.70 0.18 -214 Side (Left Side Wall) -0.70 -214 Roof -1.30 -355 Notes:

1. The Cp value is taken for L/B = 496/438 1.13.

2. The gust effect factor, G=0.85 considering the HSM-MX as rigid.

Page A.3.9.4-23 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.4-2 Design Pressures for Tornado Wind Flowing from Right Side to Left Side Wall and Vice Versa Max. Design Internal Pressure, Velocity External Pressure qv*(G*Cp-Pressure, qv Pressure Coefficient, GCpi)

Component (psf) Coefficient, Cp (GCpi) (psf)

Side (Front Row Front Wall) -0.70 -214 Side (Back Row Front Wall) -0.70 -214 Windward (Right Side Wall) 276 0.80 0.18 238 (1)

Leeward (Left Side Wall) -0.50 -167 Roof -1.30 -355 Notes:

1. The Cp value is taken for L/B = 431/438 0.88

2. The gust effect factor, G=0.85 considering the HSM-MX as rigid.

Page A.3.9.4-24 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.4-3 Spectral Acceleration Applicable to Different Components of HSM-MX for Seismic Analysis Spectral Acceleration Corresponding to Design ZPA (Design ZPA = 0.85g horizontal & 0.80g vertical) at 4% Damping at 7% Damping Frequency at 3% Damping (for steel (for concrete Direction (Hz) (for DSC) structure) components)

X (Transverse) 23.94 1.62g 1.53g 1.33g Y (Vertical) 49.02 0.80g 0.80g 0.80g Z (Longitudinal) 24.08 1.61g 1.52g 1.33g Page A.3.9.4-25 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.4-4 Load Cases for HSM-MX Concrete Components Evaluation Design Load Applicable Codes /

Design Parameters Load Type Notation References Normal Includes self-weight with 160 pcf density for ANSI/ANS 57.9-Dead DL concrete. 1984 [A.3.9.4-8]

ANSI/ANS 57.9-Design live load of 200 psf on roof which includes 1984 [A.3.9.4-8]

Live LL snow and ice load and DSC weight of 135 kip applied on DSC supports. & ASCE 7-10

[A.3.9.4-12]

140 kip of DSC insertion load is distributed to both Normal sides of the MX-RRT supports. The DSC weight RO Handling is also applied at both sides of the MX-RRT support locations (4 points).

DSC with spent fuel rejecting up to 50.0 kW of Normal TO decay heat. Extreme ambient air temp. -20 °F and Thermal 100 °F. Reference temperature = 70 °F.

Off-Normal/Accidental 135 kip of DSC insertion and retrieval load is Off-Normal applied to one side of the MX-RRT supports. The Ra Handling DSC weight is also applied at one side of the MX-RRT support locations (two points).

Enveloped of Off-Normal and Accidental Thermal Accidental (vent blocked) condition. Extreme ambient Ta Thermal temperatures -40 F and 117 °F.

Reference temperature = 70 °F NRC Reg. Guide ZPA of 0.85g in horizontal and 0.80g in vertical 1.60 [A.3.9.4-2] &

Earthquake E direction with enhancement in frequency above 9 Reg. Guide 1.61 Hz and 7% damping.

[A.3.9.4-3]

Maximum flood height of 50 ft and max. velocity 10 CFR Part 72 Flood FL of water 15 ft/sec [A.3.9.4-1]

ASCE 7-10 Wind/ [A.3.9.4-12] &

Maximum wind speed of 360 mph, and a pressure Tornado W/Wt drop of 3 psi NRC Reg Guide 1.76 Wind

[A.3.9.4-4]

Tornado NUREG-0800 Generated Wm Four types of tornado-generated missiles Section 3.5.1.4 Missile [A.3.9.4-5]

Page A.3.9.4-26 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.4-5 Load Combination for HSM-MX Concrete Components Evaluation Combination Number Load Combination Event C1 1.4 DL + 1.7 (LL + Ro) Normal C2 1.05 DL + 1.275 (LL + To + W) Off-Normal - Wind C3 1.05 DL + 1.275 (LL + To + Ra) Off-Normal - Handling C4 DL + LL + To + E Accident - Earthquake C5 DL + LL + To + Wt Accident - Tornado C6 DL + LL + To + FL Accident - Flood C7 DL + LL + Ta Accident - Thermal Note: See Table A.3.9.4-4 for notation.

Page A.3.9.4-27 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.4-6 Demand to Capacity Ratios for HSM-MX Longitudinal Reinforcement Areas Asx Asy Asip Component Thickness As,provided Governing Governing Governing Reinforcement Asx,reqd Asy,reqd Asip,reqd Name (in) (in2/in) D/Casx Load D/Casy Load D/Casip Load (in2/in) (in2/in) (in2/in)

Combination Combination Combination(1)

Bottom Unit Front 51 #9@7 0.1429 0.1304 0.91 C4 0.0703 0.49 C4 0.1287 0.45 C1 Wall Bottom Top Unit Front 51 #9@8 0.1250 0.0856 0.68 C4 0.0847 0.68 C4 0.1280 0.51 C1 Wall Bottom Front Wall Top 39 #9@8 0.1250 0.1023 0.82 C4 0.1142 0.91 C4 0.1589 0.64 C4 Bottom Unit Vent 11.5 #5@8 0.0388 0.0165 0.43 C4 0.0149 0.38 C4 0.0285 0.37 C1 Wall Top Unit Side 11 #5@8 0.0388 0.0122 0.31 C5 0.0172 0.44 C7 0.0276 0.36 C1 Vent Wall Bottom Unit Side 37 #6@8 0.0550 0.0243 0.44 C4 0.0239 0.43 C4 0.0925 0.84 C1 Wall Bottom Unit End 44 #9@8 0.1250 0.0990 0.79 C4 0.0715 0.57 C7 0.1102 0.44 C1 Side Wall Top Unit End Side 82 #9@8 0.1250 0.0449 0.36 C4 0.0570 0.46 C4 0.2047 0.82 C1 Wall Bottom Unit Rear 78 #9@8 0.1250 0.0706 0.56 C4 0.0151 0.12 C4 0.1949 0.78 C1 Wall Bottom Rear Wall 30 #9@8 0.1250 0.0088 0.07 C4 0.0000 0.00 C1 0.1350 0.54 C4 Roof Top Panel 24 #7@9 0.0667 0.0319 0.48 C2 0.0583 0.87 C5 0.0600 0.45 C1 Roof Bottom 10 #5@8 0.0388 0.0130 0.34 C5 0.0081 0.21 C7 0.0283 0.37 C3 Panel Roof Side Panel 11 #5@8 0.0388 0.0066 0.17 C5 0.0072 0.19 C2 0.0276 0.36 C1 Roof Side Panel 10.5 #5@9 0.0344 0.0038 0.11 C5 0.0126 0.37 C7 0.0551 0.80 C5 Roof Side Wall 44 #9@8 0.1250 0.0303 0.24 C5 0.1038 0.83 C2 0.1102 0.44 C1 Roof 50 #9@8 0.1250 0.0973 0.78 C2 0.0711 0.57 C5 0.1250 0.50 C1 Inclined Slab 11.5 #5@8 0.0388 0.0144 0.37 C4 0.0149 0.38 C4 0.0285 0.37 C1 Pedestal 23.89 #7@8 0.0750 0.0242 0.32 C4 0.0410 0.55 C4 0.0600 0.40 C1 Note 1:

Page A.3.9.4-28 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Asip,required is governed by minimum in-plane shear reinforcement requirement for most components. C1 is shown for such components.

Page A.3.9.4-29 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-1 HSM-MX (Back-to-Back) CAD Model Page A.3.9.4-30 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-2 HSM-MX (Back-to-Back) Meshed Model Page A.3.9.4-31 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-3 Temperature Distribution of HSM-MX for Normal Thermal Hot Condition Page A.3.9.4-32 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-4 Temperature Distribution of HSM-MXS for Blocked Vent Accident Thermal Condition Page A.3.9.4-33 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-5 HSM-MX Concrete Reinforcement Directions Page A.3.9.4-34 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 (a)

(b)

Figure A.3.9.4-6 Analytical Model of Heat Shield (a) Coupled Lower Side Heat Shield and Studs (b) Coupled Lower Top Heat Shield and Studs Page A.3.9.4-35 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-7 Horizontal Target and 5% Spectral Match (Horizontal 1, Hector Mine Earthquake)

Page A.3.9.4-36 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-8 Baseline Corrected Acceleration, Velocity and Displacement Time Histories (Horizontal 1, Hector Mine Earthquake)

Page A.3.9.4-37 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-9 Horizontal Target and 5% Spectral Match (Horizontal 2, Hector Mine Earthquake)

Page A.3.9.4-38 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-10 Baseline Corrected Acceleration, Velocity and Displacement Time Histories (Horizontal 2, Hector Mine Earthquake)

Page A.3.9.4-39 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-11 Vertical Target and 5% Spectral Match (Vertical Up, Hector Mine Earthquake)

Page A.3.9.4-40 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-12 Baseline Corrected Acceleration, Velocity and Displacement Time Histories (Vertical Up, Hector Mine Earthquake)

Page A.3.9.4-41 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-13 Lower Top Heat Shield Support Node ISRS due to Envelope of Four Earthquake-Based Motions Compatible with Enhanced RG1.60 Spectra, 4% Damping, X-Direction Page A.3.9.4-42 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-14 Lower Top Heat Shield Support Node ISRS due to Envelope of Four Earthquake-Based Motions Compatible with Enhanced RG1.60 Spectra, 4% Damping, Y-Direction Page A.3.9.4-43 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.4-15 Lower Top Heat Shield Support Node ISRS due to Envelope of Four Earthquake-Based Motions Compatible with Enhanced RG1.60 Spectra, 4% Damping, Z-Direction Page A.3.9.4-44 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.5 NUHOMS EOS-TC BODY STRUCTURAL ANALYSIS There is no change to the evaluation of the NUHOMS EOS-TC Body Structural Analysis documented in Sections 3.9.5 due to the addition of the NUHOMS MATRIX.

Page A.3.9.5-1 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.6 NUHOMS EOS FUEL CLADDING EVALUATION There is no change to the evaluation of the NUHOMS EOS fuel Cladding evaluation documented in Sections 3.9.6 due to the addition of the NUHOMS MATRIX.

Page A.3.9.6-1 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.3.9.7 NUHOMS MATRIX STABILITY ANALYSIS Table of Contents A.3.9.7 NUHOMS MATRIX STABILITY ANALYSIS ........................................... A.3.9.7-1 A.3.9.7.1 General Description ........................................................................ A.3.9.7-1 A.3.9.7.2 HSM-MX Stability Analyses .......................................................... A.3.9.7-4 A.3.9.7.3 EOS Transfer Cask Missile Stability and Stress Evaluation ...................................................................................... A.3.9.7-14 A.3.9.7.4 References ...................................................................................... A.3.9.7-15 Page A.3.9.7-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Tables Table A.3.9.7-1 Sizes and Weight for Various HSM-MX Models ........................... A.3.9.7-16 Table A.3.9.7-2 Missile Load Data for HSM-MX Stability Analysis ...................... A.3.9.7-16 Table A.3.9.7-3 Design Pressures for Tornado Wind Loading of HSM-MX ........... A.3.9.7-17 Table A.3.9.7-4 Summary of HSM-MX Sliding and Stability Results .................... A.3.9.7-17 Table A.3.9.7-5 Static analysis, Overturning and Sliding of the HSM-MX ............. A.3.9.7-18 Table A.3.9.7-6 Summary of Displacement of HSM-MX relative to the ISFSI pad for nominal concrete density (150 pcf) ........................................... A.3.9.7-19 Page A.3.9.7-ii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Figures Figure A.3.9.7-1 HSM-MX Dimensions for Stability Analysis (Static) .................... A.3.9.7-20 Figure A.3.9.7-2 Not Used ......................................................................................... A.3.9.7-21 Figure A.3.9.7-3 Not Used ......................................................................................... A.3.9.7-22 Figure A.3.9.7-4 HSM-MX Single Array Design with Five DSCs ............................ A.3.9.7-23 Figure A.3.9.7-5 Seismic Stability of DSC on HSM-MX .......................................... A.3.9.7-24 Figure A.3.9.7-6 Not Used ......................................................................................... A.3.9.7-25 Figure A.3.9.7-7 HSM-MX Maximum X-Direction Sliding TAB, =0.4 ................. A.3.9.7-26 Figure A.3.9.7-8 HSM-MXMaximum Z-Direction Sliding MIAN, =0.4 ................ A.3.9.7-27 Figure A.3.9.7-9 HSM-MX Maximum Rocking PS10, =0.8 ................................... A.3.9.7-28 Figure A.3.9.7-10 DSC Sliding on Supports during Max. HSM-MX Z-direction Sliding Case: MIAN, =0.4 ............................................................ A.3.9.7-29 Figure A.3.9.7-11 DSC Load on Supports during Max. HSM-MX Z-Direction Rocking Case: PS10, =0.8 ............................................................ A.3.9.7-30 Figure A.3.9.7-12 DSC Load on Door Opening During Max. HSM-MX Z-Direction Rocking Case: PS10, =0.8 ............................................................ A.3.9.7-31 Figure A.3.9.7-13 Horizontal Time History Set 1, HEC - Global X Direction ........... A.3.9.7-32 Figure A.3.9.7-14 Vertical Time History Set 1, HEC - Global Y Direction ............... A.3.9.7-33 Figure A.3.9.7-15 Horizontal Time History Set 1, HEC - Global Z Direction ........... A.3.9.7-34 Page A.3.9.7-iii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.7 NUHOMS MATRIX STABILITY ANALYSIS A.3.9.7.1 General Description The system consists of the dual-purpose (transportation/storage) EOS-37PTH and EOS-89BTH DSCs, the HSM-MX and the onsite transfer cask (EOS-TC) with associated ancillary equipment. Each NUHOMS MATRIX (HSM-MX) is designed to store DSCs containing up to either 37 pressurized water reactor (PWR) or 89 boiling water reactor (BWR) spent fuel assemblies (SFAs).

The HSM-MX is a staggered, two-tiered compartment, high density, high-heat rejection, storage overpack that provides a self-contained modular structure for storage of DSCs. The HSM-MX is constructed from reinforced concrete and structural steel.

The thick concrete roof and walls of the HSM-MX provide substantial neutron and gamma shielding. The monolithic structure increases resistance to earthquakes and offers significant self-shielding. The NUHOMS MATRIX retractable roller tray (MX-RRT) delivers the DSC from the transfer cask to the HSM-MX and places it on the DSC supports.

The HSM-MX storage modules can be arranged in both single row or back-to-back row arrays. The HSM-MX assembly considered for the stability evaulaution is in a single row array, having three lower compartments and two upper compartments.

A.3.9.7.1.1 HSM-MX Stability Evaluation The sliding and overturning stability analyses due to design basis wind, flood, and massive missile impact loads are performed using hand calculations. A non-linear dynamic seismic stability analysis is performed using LS-DYNA [A.3.9.7-7].

A.3.9.7.1.2 Material Properties The HSM-MX assembly is constructed of reinforced concrete and steel. The analyses consider rigid body motions. Therefore, the mechanical properties of the materials are not used as design inputs in the evaluations. The non-linear dynamic evaluation performed using LS-DYNA for the seismic loads, consists of simplified models of the HSM-MX and DSCs representative of their global masses and inertia properties.

A.3.9.7.1.3 Mass Properties The mass properties of the HSM-MX are listed in Table A.3.9.7-1. Bounding values of concrete density (140 pcf) are considered for static analyses. Nominal concrete density of 150 pcf is considered for the non-linear dynamic seismic evaluation.

Page A.3.9.7-1 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.7.1.4 Friction Coefficients The static analyses are performed using a concrete-to-concrete friction coefficient of 0.6. The non-linear dynamic analysis for the seismic loads are performed for a range of friction coefficients for concrete against concrete, varying from 0.8 as the upper bound, 0.6 as the nominal coefficient of friction for concrete poured directly on the independent spent fuel storage installation (ISFSI) pad and 0.4 as the lower bound.

A.3.9.7.1.5 Methodology The stability of the HSM-MX unit is evaluated for four load cases that may cause overturning and sliding of a freestanding module. These four load cases are:

Tornado-generated wind loads Massive missile impact loads Flood loads Seismic loads A.3.9.7.1.6 Assumptions

1. The analyses assume that the dynamic coefficient of friction is equal to the static coefficient. This assumption maximizes the rocking uplift displacements of the HSM-MX (particularly for the high friction coefficient analysis cases).

2. For the non-linear dynamic seismic analysis, coefficients of friction between the HSM-MX and the concrete ISFSI pad are varied between a lower limit of 0.4 and an upper limit of 0.8, with a single intermediate value of 0.6. The coefficients of friction for all other contact surfaces are taken as 0.25.

3. The differential pressure load caused by the tornado pressure drop does not affect the overall stability of the HSM-MX and is ignored. The structure is vented, and so any differential pressure is negligible, as the internal and external pressures equilibrate.

4. This stability evaluation is applicable to both single and double array HSM-MX design.

5. For the non-linear dynamic time history analyses, impact damping coefficients are included in all contact definitions (concrete-to-concrete and steel-to-steel) to obtain a coefficient of restitution (COR) of at least 0.8.

A.3.9.7.1.7 Loads and Boundary Conditions A.3.9.7.1.7.1 Earthquake Input The earthquake input motions are in the form of acceleration time histories whose response spectra match the Regulatory Guide 1.60 [A.3.9.7-8] response spectra for 5%

damping anchored at 0.85g zero period acceleration (ZPA) in both horizontal directions and 0.80g in the vertical direction and enhanced for frequencies above 9 Hz.

Page A.3.9.7-2 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The LS-DYNA [A.3.9.7-7] non-linear dynamic analyses are performed using seven sets of earthquake acceleration time histories. Each set consists of three orthogonal components (2 horizontal and 1 vertical), developed to match the Regulatory Guide 1.60 [A.3.9.7-8] response spectra (enhanced for frequencies above 9 Hz) and have a total approximate duration of 40 seconds. The starting seed for each set consists of actual strong motion recordings whose Fourier spectra are altered to match the target Regulatory Guide 1.60 [A.3.9.7-8] spectra (enhanced for frequencies above 9 Hz) but retains the phase spectra of the actual strong motion record. The horizontal time histories are scaled to 0.85g and the vertical time histories are scaled to 0.80g. The description of each set is as follow:

1. Time History Set number 1 (HEC) is developed based on the Magnitude 7.1 Hector Mine, 1999 earthquake (digitized at 0.01 seconds).

2. Time History Set number 2 (LCN) is based on the Magnitude 7.3 Landers/Lucern earthquake of 1992 (digitized at 0.005 seconds).

3. Time History Set number 3 (PS10) is based on the Magnitude 7.9 Denali earthquake site PS-10 of 2002 (digitized at 0.005 seconds).

4. Time History Set number 4 (TAB) is based on the Magnitude 7.4 Tabas earthquake of 1978 (digitized at 0.02 seconds).

5. Time History Set number 5 (TCU) is based on the Magnitude 7.6 Taiwan, 1999 earthquake (digitized at 0.005 seconds).

6. Time History Set number 6 (SHIF) is based on the Magnitude 7.9 Wenchuan China, 2008 earthquake, Shifangbajiao site (digitized at 0.005 seconds).

7. Time History Set number 7 (MIAN) is based on the Magnitude 7.9 Wenchuan China, 2008 earthquake, Mianzhuqingping site (digitized at 0.005 seconds).

Each component in each of the seven time history sets meets the spectral matching requirements of NUREG/CR-6728 [A.3.9.7-5].

A.3.9.7.1.7.2 Wind and Tornado Input The HSM-MX is evaluated for overturning and sliding due to the design basis tornado (DBT) specified in Appendix A.2. The DBT is based on the NRC Regulatory Guide 1.76 [0] Region I Intensities. The maximum wind speed is 360 mph. The tornado loads are generated for three separate loading phenomena, as follows, which are combined in accordance with Section 3.3.2 of NUREG-0800 [A.3.9.7-1] (i.e. tornado wind load is concurrent with (additive to) tornado missile loads).

1. Pressure or suction forces created by drag as air impinges and flows past the HSM-MX with a maximum tornado wind speed of 360 mph.

2. Suction forces due to a tornado generated pressure drop or differential pressure load of 3 psi.

3. Impact forces created by tornado-generated missiles impinging on the HSM-MX.

Per NUREG-0800, the total tornado load on a structure is combined as follows:

Wt = Wp Wt = Ww + 0.5Wp + Wm Where, Page A.3.9.7-3 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Wt = Total tornado load Ww = Load from tornado wind effect Wp = Load from tornado atmospheric pressure change effect Wm = Load from tornado missile impact effect Note that Wp is not applicable to the stability analysis as discussed in Section A.3.9.7.1.6. Thus, the load combination for tornado loading for this analysis is simplified to:

Wt = Ww + Wm In addition, a 1.1 factor is added to Dead weight + Tornado load. (Table 3-3 of NUREG-1536 [A.3.9.7-3])

The envelope of a range of missiles from Chapter 2 is used for the missile impact load.

As shown in Table A.3.9.7-2, the automobile impact on to the HSM-MX has the maximum momentum and is considered as bounding evaluation.

A.3.9.7.1.7.3 Flood Input The HSM-MX is evaluated for a flood height of 50 feet with a water velocity of 15 fps.

In addition, a 1.1 factor is added to Dead weight + Flood load (Table 3-3 of NUREG-1536 [A.3.9.7-3]).

A.3.9.7.2 HSM-MX Stability Analyses The load categories associated with the HSM-MX stability analysis are described in the previous section. The analysis steps and results for each load category are presented in this section.

A.3.9.7.2.1 Design Basis Tornado Wind and Missile Loads The HSM-MX is evaluated for forces created by drag as air impinges and flows past the HSM-MX with a maximum tornado wind speed of 360 mph.

For sliding and overturning analysis, it is assumed that the module is subjected to the load due to 238 psf windward pressure load acting on the front wall. The leeward side of the same module is subjected to a wind suction load of 167 psf. A suction of 355 psf is applied to the roof. These loads are shown in Table A.3.9.7-3.

In addition, missiles loads are combined with the tornado wind load per NUREG-800

[A.3.9.7-1] and NUREG-1536 [A.3.9.7-3].

Static Overturning Analysis due to Tornado Wind The empty HSM-MX will rotate about B, shown in Figure A.3.9.7-1.

Page A.3.9.7-4 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 In the overturning analysis of the HSM-MX, the effects of tornado wind forces are first determined. An overturning moment is then calculated and is compared with a stabilizing moment. The safety factor against overturning computed for the HSM-MX due to tornado wind is 3.28, which includes a factor of 1.1 Dynamic Overturning Analysis of Tornado Wind Concurrent with Massive Missile Impact Loading A dynamic analysis based on the conservation of energy is conducted for the combined effects of wind and concurrent massive missile impact loading. The effects of the concurrent massive missile impact loads are used in determining the initial angular momentum from the conservation of angular momentum equation using the wind loads from the previous section. Then the angle of rotation is determined from the conservation of energy of the concurrent loading.

The wind loads are calculated conservatively for HSM-MX single array:

Horizontal = ( + )( )( )

Vertical: = ( )( )( )

The concurrent wind loading is accounted for by reducing the inertia that resists motion in the denominator of the equation.

=

2 + 2 2

( ) (2) ( ) ( 2 )

Where, Fhw = Horizontal tornado wind load Fvw = Vertical tornado wind load B = Angle of rotation mm = Mass of the missile dm = Distance from missile impact to floor vi = Initial missile velocity Itot = Total moment of inertia of HSM-MX h = Height of HSM-MX w = Width of HSM-MX The conservation of energy is used for overturning.

Rotational Kinetic Energy = Change in Potential Energy - Work Done by Horizontal Wind force 2

Itot 2

= ( ) [sin( + ) ] [cos( + ) ]

Page A.3.9.7-5 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Where,

= Angle of tipping

= Angle from the horizontal to center of gravity (CG) of HSM-MX (52.1°)

r = Diagonal distance from CG to point B Itot = Total moment of Inertia of HSM-MX W = Weight of the empty HSM-MX The HSM-MX is stable against overturning as tip-over does not occur until the CG rotates past the edge (point B, Figure A.3.9.7-1) of the HSM-MX to an angle of more than 90°- 52.1° = 37.9°. The HSM-MX rotates a maximum of 0.000029 degrees, which includes a factor of 1.1 and is less than the 37.9 degrees required to overturn the module.

Time-Dependent Overturning Analysis of Tornado Wind Concurrent with Massive Missile Impact Loading In addition to the dynamic overturning analysis, a time dependent analysis is used to ensure the absence of any overturning.

An approximate relationship for the deceleration of an automobile impacting a rigid wall is given by:

-x = 12.5g x Eq. D-1 of [A. 3.9.7-4]

where, x = Deceleration (ft/sec2)

= Distance automobile crushes into target (ft)

A force time history is obtained:

= 0.625 20 . 6 of [. 3.9.7 4]

The overturning moment is:

= +

2 Where, dm = Distance from missile impact to floor h = Vertical height to the top of HSM-MX and is a function of rotation The stabilizing moment is:

= ( ) ( + )

Where, Page A.3.9.7-6 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 WHSM = Weight of the loaded HSM-MX r = Diagonal distance from CG to point B

= Angle of rotation The moment causing acceleration is:

=

The angular velocity is:

, + ,1

= [ ( 1 )] + 1 2

Where, i = Index for current time step i-1 = Index for previous time step Itot = Total moment of Inertia of HSM-MX The angle of rotation is:

+ 1

= [ ( 1 )] + 1 2

The angle of rotation is zero as the overturning moment due to missile impact and wind loading is less than the resisting moment.

Sliding Analysis for Tornado Wind Concurrent with Massive Missile Impact loading The combined wind + missile impact case is considered for HSM-MX sliding analysis based on the conservation of energy.

First, the conservation of momentum is used for the sliding analysis.

=

+ /386.4 Where, V = Initial linear velocity of module after impact vi = Initial velocity of missile m = Mass of the missile M = Mass of the HSM-MX Then using the conservation of energy:

= +

( + ) 2

( ) = +

2 Page A.3.9.7-7 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Where,

= 0.6 coefficient of friction for concrete-to-concrete surfaces Fvw = Uplift force generated by DBT wind pressure on the roof d = Sliding distance of HSM-MX Fhw = Sliding force generated by DBT wind pressure The sliding distance of the HSM-MX module is calculated to be 0.15 inches, which includes a factor of 1.1.

Time-Dependent Sliding Analysis for Tornado Wind Concurrent with Massive Impact Loading In addition to the dynamic sliding analysis, a time dependent analysis is used to provide a bounding sliding displacement.

The total force causing sliding is:

= +

The resisting force from friction is:

= ( )

Therefore the force causing acceleration is:

=

The velocity is:

, + ,1

= [ ( 1 )] + 1 2

Where, i = Index for current time step i-1 = Index for previous time step mtot= Total mass of empty HSM-MX The sliding displacement is:

+ 1

= [ ( 1 )] + 1 2

The sliding displacement is zero as the sliding force due to missile impact and wind loading is less than the resisting force.

Page A.3.9.7-8 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.7.2.2 Flood Loads The HSM-MX is designed for a flood height of 50 feet and water velocity of 15 fps.

The module is evaluated for the effects of a water current of 15 fps impinging on the side of a submerged HSM-MX. Under 50 feet of water, the inside of the module is rapidly filled with water. Therefore, the HSM-MX components are not evaluated for the 50 feet static head of water.

Calculation of the drag pressure due to design flood is shown in Appendix A.3.9.4.9.3.

Overturning Analysis The factor of safety against overturning of an empty HSM-MX, for the postulated flooding conditions, is calculated by summing moments about the bottom outside corner of a single array HSM-MX. The factor of safety against overturning of the HSM-MX due to the postulated design basis flood water velocity is 1.98 inches, which includes a factor of 1.1.

Sliding Analysis The factor of safety against sliding of a freestanding single array HSM-MX due to the maximum postulated flood water velocity of 15 fps is calculated using methods similar to those described above. The effective weight of the HSM-MX acting vertically downward, less the effects of buoyancy acting vertically upward is calculated. The factor of safety against sliding for a single array HSM-MX due to the postulated design basis flood water velocity is 1.42 inches, which includes a factor of 1.1.

A.3.9.7.2.3 Seismic Loads The static sliding and overturning analysis for the seismic loads are performed to determine the maximum seismic accelerations before HSM-MX starts sliding or overturning. Non-linear dynamic analysis is performed using LS-DYNA for the earthquake inputs discussed in A.3.9.7.1.7.1 to determine the maximum sliding and overturning distances.

A.3.9.7.2.3.1 Low Seismic Load HSM-MX static overturning analysis The stabilizing moment due to the components dead weight and the overturning moment due to the seismic forces are calculated and compared. The 1.1 coefficient of the load combination (Table 3-3 of NUREG-1536 [A.3.9.7-3]) is conservatively applied to the overturning moment only. Both the maximum HSM-MX concrete density (160 pcf) with maximum DSC weight (to maximize the overturning moment) and minimum HSM-MX concrete density (140 pcf) with minimum DSC weight (to minimize the stabilizing moment) are considered. The overturning analysis is done considering the smallest distance from the HSM-MX center of gravity to HSM-MX corner point B (Figure A.3.9.7-1).

Page A.3.9.7-9 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.7-5 shows the results. The safety factor 1.1 is less than 1, meaning the HSM-MX can have some lifting under the seismic loads. The non-linear dynamic analyses (Section A.3.9.7.2.3.2) estimate the amount of lifting for high seismic loads.

The maximum acceptable accelerations before any lifting occurs are = 0.40g and 2

= 0.60g (assuming = 3 )

HSM-MX static sliding analysis The resisting friction force and horizontal seismic force are calculated and compared.

The 1.1 coefficient of the load combination (Table 3-3 of NUREG-1536 [A.3.9.7-3])

is conservatively applied to the horizontal seismic force only.

Resisting friction force: = (1 0.4 )  :

Horizontal seismic force: =

Safety factor: = 1.1 = (1 0.4 )/(1.1 )

For static sliding analysis of the HSM-MX, the safety factor is independent of the weight considered. It only depends on the coefficient of friction and accelerations.

Table A.3.9.7-5 shows the results for a nominal coefficient of friction of 0.6 and gives a safety factor of 0.44. The HSM-MX will slide under 0.85g horizontal and 0.80g vertical loads. The non-linear dynamic analyses (Section A.3.9.7.2.3.2) estimate the amount of sliding for high seismic loads.

The maximum acceptable accelerations before any sliding occurs are = 0.32g and 2

=0.48g (assuming = 3 )

Seismic Stability of the DSC on DSC Supports inside the HSM-MX This evaluation is performed for the DSC resting on the supports inside the HSM-MX, which includes the stability of the DSC against lifting off from one of the support during a seismic event and potential sliding off of the DSC from the supports. The horizontal equivalent static acceleration of 0.85g is applied laterally to the center of gravity of the DSC. The point of rigid body rotation of the DSC is assumed to be the center of the support, point of contact with the DSC (as shown in Figure A.3.9.7-5).

The applied moment acting on the DSC is calculated by summing the overturning moments.

The stabilizing moment, acting to oppose the overturning moment, is calculated by subtracting the effects of the upward vertical seismic acceleration of 0.80g from the total weight of the DSC and summing moments at the point of rigid body rotation.

Figure A.3.9.7-5 shows a DSC on its front and rear DSC supports and define the geometric parameters and loads used below.

Page A.3.9.7-10 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Stabilizing moment:

= ( 1.1 ) with = 0.4 = sin Overturning moment:

= 1.1 with = = cos Safety coefficient:

1 0.44

= = tan 1.1 For DSC overturning analysis, the safety factor is independent of the DSC weight or radius considered. It only depends on the support angle and the accelerations. The minimum support angle to avoid DSC overturning (Figure A.3.9.7-5) is 55.3°.

Assuming = 23 , the maximum seismic accelerations are 0.54g horizontal and 0.36g vertical before DSC overturning occurs A.3.9.7.2.3.2 High Seismic Load Non-Linear Dynamic Time-History Analyses of HSM-MX for High Seismic Loads LS-DYNA Finite Element Model HSM-MX A finite element model (FEM) of the HSM-MX monolithic expansion single array design loaded with five DSCs was created for use with LS-DYNA [A.3.9.7-7]. The HSM-MX unit and DSC are constructed with solid 4-node tetrahedral elements for meshing simplicity, whereas the IFSFI pad includes 8-node solids elements. All components are modeled with rigid materials for the stability analysis. The FEM includes the DSC axial retainers modeled with 0.5 inch gap to the DSC, the front and rear DSC supports with stop plates and five front doors and top vent covers.

The model does not include the metallic components (heat shields, etc.) which are not structurally important for the stability analysis. Their weight is accounted for in the total weight of the HSM-MX.

The HSM-MX rests on top of the ISFSI concrete pad and is free to slide or rock when subjected to the forces resulting from the prescribed pad seismic accelerations. In the FEM, contacts are defined between the HSM-MX and the ISFSI pad as well as between the DSCs with their front and rear DSC supports and parts of the HSM-MX concrete that could be in contact with the DSCs if they lift from their supports.

Contact definitions are included between all interfacing parts using contacts algorithm in LS-DYNA.

Contacts are defined for the following interfaces:

HSM-MX to basemat, no initial gap Page A.3.9.7-11 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 DSC to for supports, no initial gap DSC to rear stop plate, no initial gap DSC to HSM-MX front circular opening, initial 1.5 gap between DSC Ø75.5 and the door opening Ø78.5 DSC to front axial retainer, initial gap of 0.5 Coefficient of Restitution The coefficient of restitution is defined as the ratio of the velocity of a body immediately after impact to its velocity immediately prior to impact. A coefficient of restitution equal to 0 means a perfectly plastic impact in which the impacting body sticks to the impacted body. A coefficient of restitution equal to 1 means a perfectly elastic impact in which the impacting body bounces off the impacted body with no energy loss. For the case of concrete impacting against concrete, a reasonable coefficient of restitution is in the order of 0.1 since a concrete body does not bounce upon impacting on a concrete surface. For the LS-DYNA analyses, a coefficient of restitution of at least 0.8 is used as a conservative value. The coefficient of restitution is inputted into LS-DYNA analyses as the parameter viscous damping coefficient

((VDC) in percent of critical) of the surface-to-surface contact.

Non-Linear Dynamic Analyses The seismic analyses inputs as described in Section A.3.9.7.1.7.1 consist of three components of acceleration in the form of earthquake time histories applied to the ISFSI pad. Thus, all nodal points of the pad move as prescribed by these input motions. Examples of the input motion displacement, velocity and acceleration histories used in LS-DYNA analysis are shown in Figure A.3.9.7-13, Figure A.3.9.7-14 and Figure A.3.9.7-15 in the global X, Y, and Z directions, respectively, for the motion derived from the Hector Mine (HEC) earthquake. The three components of the acceleration time histories are applied simultaneously in each of the three orthogonal directions. Each of the seven time history sets are analyzed with three different coefficients of friction (0.4, 0.6, and 0.8) for a total of 21 computer runs.

In order to obtain the sliding displacement of the HSM-MX relative to the pad, the change in X-lengths and change in Z-lengths (Figure A.3.9.7-4) between the four HSM-MX corner nodes and one ISFSI pad node are plotted over time.

Two uplift values are reported, one each for rotation about the global X and Z axes.

For rocking about the X-axis, the change in the vertical (global Y) distance between the +Z and -Z node pairs is plotted and tabulated. For rocking about the Z axis, the change in the vertical distance between the +X and -X node pairs is plotted and tabulated.

The gaps between the DSCs and front axial retainers are verified against the DSC sliding on the support. Also, the loads on the DSC supports are verified against the uplift.

Page A.3.9.7-12 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The maximum values over time for sliding and rocking movements from the seven time histories are used to get the computed response as the median value plus 1 standard deviation (shown in Table A.3.9.7-6). This methodology is in accordance with NUREG/CR-6865 [A.3.9.7-6]

A.3.9.7.2.4 Results Table A.3.9.7-4 through Table A.3.9.7-6 show a summary of the results from the analyses performed in Section A.3.9.7.2.

For flood, wind, and missile impact, it is determined that the uplift and sliding values are small for the HSM-MX. Therefore, the DSC remains stable on the front and rear DSC supports inside the HSM-MX.

The maximum seismic acceleration before HSM-MX sliding or overturning occurs are 0.48g horizontal and 0.32g vertical for a coefficient friction of 0.6 between the HSM-MX and the ISFSI pad. The non-linear dynamic analysis shows a maximum resultant sliding of 12.5 inches and a maximum uplift of 0.13 inches for the set of seismic earthquake inputs.

Figure A.3.9.7-7 and Figure A.3.9.7-8 show the maximum sliding results in both horizontal directions, and Figure A.3.9.7-9 shows the maximum rocking for the input earthquake loads. On each sliding plots (Figure A.3.9.7-7 and Figure A.3.9.7-8), the four curves represent the displacement of each bottom corner of the HSM-MX relative to the ISFSI pad. For the rocking plot (Figure A.3.9.7-9), the two curves represents the relative vertical displacement between 2 HSM-MX bottom corners.

Figure A.3.9.7-10 shows the sliding of five DSCs on the front and rear DSC supports.

Figure A.3.9.7-11 shows total load on four support for all five DSCs. The sliding fluctuates in the range of 0 to 0.5 inches, which is the initial gap in front axial retainer.

Figure A.3.9.7-12 shows the load between the DSC shell and circular opening on the front door. There is no contact between the DSC and the HSM-MX. Therefore, DSCs do not lift from their supports during a seismic event.

A.3.9.7.3 EOS Transfer Cask Missile Stability and Stress Evaluation There is no change to the EOS transfer cask missile stability and stress evaluation documented in Sections 3.9.7.2 due to the addition of the HSM-MX.

Page A.3.9.7-13 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.3.9.7.4 References A.3.9.7-1 NUREG-0800, Standard Review Plan, Missiles Generated by Natural Phenomena, Revision 2, U.S. Nuclear Regulatory Commission, July 1981.

A.3.9.7-2 American Society of Civil Engineers, ASCE 7-10, Minimum Design Loads for Buildings and Other Structures.

A.3.9.7-3 NUREG-1536 Revision 1, Standard Review Plan for Spent Fuel Dry Storage Systems at a General License Facility, July 2010, U.S. Nuclear Regulatory Commission.

A.3.9.7-4 Bechtel Report BC-TOP-9A Rev. 2, Topical Report - Design of Structures for Missile Impact, September 1974.

A.3.9.7-5 NUREG/CR-6728, Technical Basis for Revision of Regulatory Guidance on Design Ground Motions: Hazard- and Risk-consistent Ground Motion Spectra Guidelines, October 2001, Prepared by Risk Engineering, Inc. for U.S. Nuclear Regulatory Commission.

A.3.9.7-6 NUREG/CR-6865, Parametric Evaluation of Seismic Behavior of Freestanding Spent Fuel Dry Cask Storage Systems, February 2005, U.S. Nuclear Regulatory Commission.

U. S. Nuclear Regulatory Commission, Regulatory Guide 1.76, Design Basis Tornado for Nuclear Power Plants, Revision 1, March 2007.

A.3.9.7-7 LS-DYNA Version 7.0.0, Rev. 79055, Livermore Software Technology Corporation (LSTC).

A.3.9.7-8 NRC Regulatory Guide 1.60, Design Response Spectra for Seismic Design of Nuclear Power Plants, Rev. 1, December 1973.

A.3.9.7-9 U.S. Nuclear Regulatory Commission, Regulatory Guide 1.76, Design Basis Tornado and Tornado Missiles for Nuclear Power Plants, Rev. 1, March 2007.

Page A.3.9.7-14 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.7-1 Sizes and Weight for Various HSM-MX Models Total Length of Nominal Weight of Empty HSM-MX HSM-MX Module HSM-MX (in.) (kips)(1)

HSM-MX Single Array 277 2.355 HSM-MX Double Array 496 3,945 Notes:

(1) The nominal weights for the HSM-MX are based on concrete density of 150 pcf.

Table A.3.9.7-2 Missile Load Data for HSM-MX Stability Analysis Velocity Momentum Missile Mass (lbs.) Dimensions (fps) (lbs-fps) 13.5 Diameter Utility Wooden Pole 1,124 180 202,320 35 Long Armor Piercing 276 8 Diameter 185 51,060 Artillery Shell 12 Sch. 40 Steel Pipe 750 154 115,500 15 Long Automobile 4,000 20 ft2 Contact Area 195 780,000 Page A.3.9.7-15 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.7-3 Design Pressures for Tornado Wind Loading of HSM-MX Wall Velocity Ext. Pressure Int. Pressure Max/Min Design Orientation(1) Pressure (psf) Coefficient (2) Coefficient (3) Pressure (psf) (4)

Front 276.4 0.680 237.7 Left 276.4 -0.595 -214.2 (5)

Rear 276.4 -0.425 +/- 0.18 -167.2 Right 276.4 -0.595 -214.2 Top 276.4 -1.105 -355.2 Notes:

(1) Wind direction assumed to be from front. Wind loads from other directions may be found by rotating above table values to desired wind direction.

(2) These values are calculated using the external pressure coefficients from Figure 27.4-1 of [A.3.9.7-2] times the gust effect factor (0.85) from Section 26.9 of [A.3.9.7-2]

(3) Internal pressure coefficient taken from Table 26.11-1 of [A.3.9.7-2]

(4) These values are computed based on Equation 27.4-1 of [A.3.9.7-2]

(5) The bounding Cp of -0.5 from an L/B ratio of 0-1 is used for wind in all directions from Figure 27.4-1 of

[A.3.9.7-2]

Table A.3.9.7-4 Summary of HSM-MX Sliding and Stability Results Loading Tornado Wind + Missile(1) Flood Maximum Maximum Safety Safety Factor Sliding Rocking Factor Result against Distance Uplift against Sliding (in) (º) Tipping HSM-MX Single 0.15 0.000029 1.42 1.98 Array Notes:

(1) 1.1 Factor Included.

Page A.3.9.7-16 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.7-5 Static analysis, Overturning and Sliding of the HSM-MX Concrete Density [pcf] 140 160 Overturning Moment [in.kips] 463,757 523,739 Stabilizing Moment [in.kips] 344,115 383,056 (1)

Overturning Safety Factor 0.67 0.66 Max accelerations before = 23 0.41 0.40 overturning 0.61 0.60 Horizontal Seismic Force [kips] 2126 2408 (3)

Resisting Friction Force [kips] 1021 1156 (2)

Sliding Safety Factor 0.44 Max accelerations before = 23 0.32 sliding 0.48 Notes:

(1) SF=Mst/1.1Mot (2) SF=Ffr/1.1Fhs (3) Nominal Coefficient of friction 0.6 Page A.3.9.7-17 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.3.9.7-6 Summary of Displacement of HSM-MX relative to the ISFSI pad for nominal concrete density (150 pcf)

Coefficient of X-Displ. Z-Displ. Resultant X-Rocking Z-Rocking Earthquake Friction [in](2) [in](2) [in](1) [in] [in]

0.4 7.29 3.53 7.61 0.00 0.00

1. HEC 0.6 2.45 2.08 2.55 0.00 0.02 0.8 1.59 1.11 1.65 0.01 0.06 0.4 6.79 7.99 9.11 0.00 0.00

2. LCN 0.6 3.83 5.52 6.65 0.00 0.02 0.8 2.66 3.12 3.94 0.02 0.13 0.4 9.32 6.76 10.75 0.00 0.00

3. PS10 0.6 5.13 3.36 6.12 0.00 0.07 0.8 2.69 1.12 2.91 0.01 0.14 0.4 9.84 7.00 11.51 0.00 0.00

4. TAB 0.6 5.39 3.78 6.48 0.00 0.02 0.8 1.98 1.13 2.22 0.01 0.05 0.4 9.14 4.22 9.52 0.00 0.00

5. TCU 0.6 3.73 1.40 3.77 0.00 0.02 0.8 1.51 0.51 1.53 0.01 0.07 0.4 8.49 9.57 12.77 0.00 0.00

6. SHIF 0.6 3.69 7.74 8.57 0.00 0.02 0.8 2.35 4.63 5.19 0.01 0.10 0.4 5.13 11.47 11.51 0.00 0.00

7. MIAN 0.6 3.19 7.69 8.11 0.00 0.02 0.8 1.91 4.54 4.84 0.02 0.11 0.4 9.84 11.47 12.77 0.00 0.00 Maximum 0.6 5.39 7.74 8.57 0.00 0.07 0.8 2.69 4.63 5.19 0.02 0.14 0.4 8.00 7.22 10.40 0.00 0.00 Average 0.6 3.92 4.51 6.04 0.00 0.03 0.8 2.10 2.31 3.18 0.01 0.09 0.4 8.49 7.00 10.75 0.00 0.00 Median 0.6 3.73 3.78 6.48 0.00 0.02 0.8 1.98 1.13 2.91 0.01 0.10 0.4 10.16 9.80 12.50 0.00 0.00 Median + 0.6 4.77 6.33 8.66 0.00 0.04 0.8 2.46 2.88 4.41 0.01 0.13 (1) The resultant displacement is the square root of the sum of the squares of the X- and Z-displacements over time.

This is not the resultant of the maximum X- and Z-Displacements (2) Absolute values are reported = max(abs(u(t)))

Page A.3.9.7-18 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.7-1 HSM-MX Dimensions for Stability Analysis (Static)

Page A.3.9.7-19 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.7-2 Not Used Page A.3.9.7-20 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.7-3 Not Used Page A.3.9.7-21 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.7-4 HSM-MX Single Array Design with Five DSCs Page A.3.9.7-22 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.7-5 Seismic Stability of DSC on HSM-MX Page A.3.9.7-23 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.7-6 Not Used Page A.3.9.7-24 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.7-7 HSM-MX Maximum X-Direction Sliding TAB, =0.4 Page A.3.9.7-25 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.7-8 HSM-MX Maximum Z-Direction Sliding MIAN, =0.4 Page A.3.9.7-26 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.7-9 HSM-MX Maximum Rocking PS10, =0.8 Page A.3.9.7-27 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.7-10 DSC Sliding on Supports during Max. HSM-MX Z-direction Sliding Case:

MIAN, =0.4 Page A.3.9.7-28 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.7-11 DSC Load on Supports during Max. HSM-MX Z-Direction Rocking Case:

PS10, =0.8 Page A.3.9.7-29 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.3.9.7-12 DSC Load on Door Opening During Max. HSM-MX Z-Direction Rocking Case: PS10, =0.8 Page A.3.9.7-30 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Horizontal Acceleration Time History, H1 Horizontal Velocity Time History, H1 Horizontal Displacement Time History, H1 Figure A.3.9.7-13 Horizontal Time History Set 1, HEC - Global X Direction Page A.3.9.7-31 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Vertical Acceleration Time History, V

Vertical Velocity Time History, V

Vertical Displacement Time History, V

Figure A.3.9.7-14 Vertical Time History Set 1, HEC - Global Y Direction Page A.3.9.7-32 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Horizontal Acceleration Time History, H2 Horizontal Velocity Time History, H2 Horizontal Displacement Time History, H2 Figure A.3.9.7-15 Horizontal Time History Set 1, HEC - Global Z Direction Page A.3.9.7-33 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.4 THERMAL EVALUATION Table of Contents A.4 THERMAL EVALUATION ........................................................................................ A.4-1 A.4.1 Discussion of Decay Heat Removal System ................................................. A.4-2 A.4.2 Material and Design Limits........................................................................... A.4-3 A.4.2.1 Summary of Thermal Properties of Materials .................................. A.4-3 A.4.3 Thermal Loads and Environmental Conditions ......................................... A.4-4 A.4.4 Thermal Evaluation for Storage ................................................................... A.4-5 A.4.4.1 EOS-37PTH DSC and Basket Type 4H - Description of Load Cases for Storage .............................................................................. A.4-6 A.4.4.2 EOS-37PTH DSC with Basket Type 4H - Thermal Model for Storage in HSM-MX ......................................................................... A.4-7 A.4.4.3 EOS-37PTH DSC with Basket Type 4H for HLZC 7 -Storage Evaluation ....................................................................................... A.4-17 A.4.4.4 EOS-37PTH DSC with Basket Type 4L/5 - Storage in HSM-MX .................................................................................................. A.4-22 A.4.4.5 EOS-89BTH DSC with Basket Type 3 - Storage in HSM-MX...... A.4-26 A.4.5 Thermal Evaluation for Storage in Updated HSM-MX ........................... A.4-27 A.4.5.1 Design Changes in Updated HSM-MX .......................................... A.4-27 A.4.5.2 Description of Load Cases for Storage in Updated HSM-MX ....... A.4-28 A.4.5.3 Thermal Model for Storage in Updated HSM-MX......................... A.4-28 A.4.5.4 EOS-37PTH DSC with Basket Type 4H - Storage in Updated HSM-MX ........................................................................................ A.4-29 A.4.5.5 EOS-37PTH DSC with Basket Type 4L/5 - Storage in Updated HSM-MX ........................................................................................ A.4-31 A.4.5.6 EOS-89BTH DSC with Basket Type 3 - Storage in Updated HSM-MX ........................................................................................ A.4-32 A.4.5.7 Sensitivity Study ............................................................................. A.4-33 A.4.6 References ..................................................................................................... A.4-38 Page A.4-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Tables Table A.4-1 EOS-37PTH DSC in HSM-MX, Design Load Cases for Storage Conditions with HLZC 7 .............................................................................. A.4-2 Table A.4-2 Maximum Fuel Cladding and Concrete Temperatures for Storage Conditions of EOS-37PTH DSC in HSM-MX with HLZC 7 ...................... A.4-2 Table A.4-3 Maximum Temperatures of Key Components in HSM-MX loaded with EOS-37PTH DSC with HLZC 7 ................................................................... A.4-2 Table A.4-4 Average Temperatures of Key Components in HSM-MX loaded with EOS-37PTH DSC with HLZC 7 ................................................................... A.4-2 Table A.4-5 GCI Calculations Based on LC 1e and LC 1f for HSM-MX Loaded with EOS-37PTH DSC ......................................................................................... A.4-2 Table A.4-6 Summary of Air Temperatures and Mass Flow Rates at Inlet and Outlet of EOS-37PTH DSC in HSM-MX with HLZC 7 ......................................... A.4-2 Table A.4-7 Comparison of Average Gas Temperature in EOS-37PTH DSC Cavity ..... A.4-2 Table A.4-8 EOS-37PTH DSC in HSM-MX, Design Load Cases for Storage Conditions with HLZCs 8 and 9 ................................................................... A.4-2 Table A.4-9 Maximum Fuel Cladding and Concrete Temperatures for Storage Conditions of EOS-37PTH DSC in HSM-MX with HLZCs 8 and 9 ........... A.4-2 Table A.4-10 Maximum Temperature of Key Components in HSM-MX Loaded with EOS-37PTH DSC with HLZCs 8 and 9 ....................................................... A.4-2 Table A.4-11 Average Temperature of Key Components in HSM-MX Loaded with EOS-37PTH DSC with HLZCs 8 and 9 ....................................................... A.4-2 Table A.4-12 Comparison of Maximum Temperature between HLZCs 8 and 9 with HLZC 7 ......................................................................................................... A.4-2 Table A.4-13 Comparison of EOS-89BTH DSC Temperatures in HSM-MX and EOS-TC125/TC108 ...................................................................................... A.4-2 Table A.4-14 EOS-37PTH DSC in Updated HSM-MX, Design Load Cases for Storage Conditions with HLZC 7 ................................................................. A.4-2 Table A.4-15 Summary of Convergences of Steady CFD Model of EOS-37PTH DSC in Updated HSM-MX ................................................................................... A.4-2 Table A.4-16 Maximum Fuel Cladding and Concrete Temperatures for Storage Conditions of EOS-37PTH DSC in Updated HSM-MX with HLZC 7 ........ A.4-2 Table A.4-17 Maximum Temperatures of Key Components in Updated HSM-MX loaded with EOS-37PTH DSC with HLZC 7 ............................................... A.4-2 Table A.4-18 Average Temperatures of Key Components in Updated HSM-MX loaded with EOS-37PTH DSC with HLZC 7 ............................................... A.4-2 Page A.4-ii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.4-19 GCI Calculations Based on LC 1e-S and LC 1f-S for Updated HSM-MX Loaded with EOS-37PTH DSC .................................................................... A.4-2 Table A.4-20 Summary of Air Temperatures and Mass Flow Rates at Inlet and Outlet of EOS-37PTH DSC in Updated HSM-MX with HLZC 7 .......................... A.4-2 Table A.4-21 Comparison of Average Gas Temperature in EOS-37PTH DSC Cavity ..... A.4-2 Table A.4-22 EOS-37PTH DSC in Updated HSM-MX, Design Load Cases for Storage Conditions with HLZCs 8 and 9 ...................................................... A.4-2 Table A.4-23 Maximum Fuel Cladding and Concrete Temperatures for Storage Conditions of EOS-37PTH DSC in Updated HSM-MX with HLZCs 8 and 9 ........................................................................................................... A.4-2 Table A.4-24 Maximum Temperature of Key Components in Updated HSM-MX Loaded with EOS-37PTH DSC with HLZCs 8 and 9 .................................. A.4-2 Table A.4-25 Average Temperature of Key Components in Updated HSM-MX Loaded with EOS-37PTH DSC with HLZCs 8 and 9 .................................. A.4-2 Table A.4-26 Comparison of Maximum Temperature between HLZCs 8 and 9 with HLZC 7 ......................................................................................................... A.4-2 Table A.4-27 Comparison of EOS-89BTH DSC Temperatures in Updated HSM-MX and EOS-TC125/TC108 ............................................................................... A.4-2 Table A.4-28 Maximum Fuel Cladding and Concrete Temperatures for Periodic and Symmetric Models ........................................................................................ A.4-2 Table A.4-29 Maximum Temperatures of Key Components in HSM-MX Loaded with EOS-37PTH DSC for Periodic and Symmetric Models ............................... A.4-2 Table A.4-30 Average Temperatures of Key Components in HSM-MX Loaded with EOS-37PTH DSC for Periodic and Symmetric Models ............................... A.4-2 Table A.4-31 Maximum Fuel Cladding and Concrete Temperatures for Bounding Storage Conditions of Middle Unit and End Unit Models ........................... A.4-2 Table A.4-32 Maximum Temperatures of Key Components in HSM-MX Loaded with EOS-37PTH DSC for Bounding Storage Conditions of Middle Unit and End Unit Models ........................................................................................... A.4-2 Table A.4-33 Average Temperatures of Key Components in HSM-MX Loaded with EOS-37PTH DSC for Bounding Storage Conditions of Middle Unit and End Unit Models ........................................................................................... A.4-2 Table A.4-33a Maximum Fuel Cladding and Concrete Temperatures in HSM-MX Loaded with EOS-37PTH DSC for Periodic and Full Models with Bounding Normal Condition ........................................................................ A.4-2 Table A.4-33b Maximum Temperatures of Key Components in HSM-MX Loaded with EOS-37PTH DSC for Periodic and Full Models with Bounding Normal Condition ...................................................................................................... A.4-2 Page A.4-iii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.4-33c Average Temperatures of Key Components in HSM-MX Loaded with EOS-37PTH DSC for Periodic and Full Models with Bounding Normal Condition ...................................................................................................... A.4-2 Page A.4-iv Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Figures Figure A.4-1 CFD Model for HSM-MX with EOS-37PTH DSC .................................... A.4-70 Figure A.4-2 HSM-MX with 90-Degree-Turn Outlet Ducts............................................ A.4-71 Figure A.4-3 Axial View of HSM-MX Storage Module with Wind Domain in Symmetrical Mid-Plane for Base Mesh ...................................................... A.4-72 Figure A.4-4 Cross-sectional View of HSM-MX Storage Module with Wind Domain in a Transverse Plane for Base Mesh .......................................................... A.4-73 Figure A.4-5 Histogram of y+ on the Outer Surface of EOS-37PTH DSC Shell in Lower and Upper Compartments of HSM-MX with HLZC 7 ................... A.4-74 Figure A.4-6 Exterior Boundary Conditions for the Side Wind Load Cases of EOS-37PTH DSC in HSM-MX........................................................................... A.4-75 Figure A.4-7 Convergence of Maximum Fuel Cladding Temperatures for all Steady-State Load Cases of EOS-37PTH DSC in HSM-MX with HLZC 7 .......... A.4-76 Figure A.4-8 HSM-MX Models Used for Verification of Simplifications within the Thermal Model ........................................................................................... A.4-77 Figure A.4-9 Temperature Profiles for HSM-MX loaded with EOS-37PTH DSC at Bounding Normal Hot Storage Condition (Load Case 1e) ......................... A.4-78 Figure A.4-10 Temperature Profiles for HSM-MX loaded with EOS-37PTH DSC at Off-Normal Hot Storage Condition (Load Case 2) .................................... A.4-81 Figure A.4-11 Temperature Profiles for HSM-MX loaded with EOS-37PTH DSC at Accident Blocked Inlet Vents Storage Condition for 32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br /> (Load Case 3) ........................................................................................................ A.4-84 Figure A.4-12 Maximum Temperature Histories of Key Components in HSM-MX loaded with EOS-37PTH DSC with HLZC 7 at Blocked Inlet Vent Accident Condition (Load Case 3) ............................................................. A.4-87 Figure A.4-13 Streamlines of Airflow inside the HSM-MX Cavity for Normal Hot Storage Condition (Load Case 1e) .............................................................. A.4-88 Figure A.4-14 Temperature Profiles for HSM-MX loaded with EOS-37PTH DSC at Bounding Normal Hot Storage Condition (Load Case 1e for HLZC 8) ..... A.4-89 Figure A.4-15 Temperature Profiles for HSM-MX loaded with EOS-37PTH DSC at Bounding Normal Hot Storage Condition (Load Case 1e for HLZC 9) ..... A.4-92 Figure A.4-16 Comparison of DSC Support used in the CFD Model in Section A.4.4.2.2 and the Sensitivity Model of HSM-MX in Section A.4.4.3.5..... A.4-95 Figure A.4-17 Comparison of HSM-MX Door Used in the CFD Model in Section A.4.4.2.2 and the Sensitivity Model in Section A.4.4.3.5 .......................... A.4-96 Figure A.4-18 Comparison of DSC Support used in the CFD Model in Section A.4.4.2.2 and the Updated Model of HSM-MX in Section A.4.5 .............. A.4-97 Page A.4-v Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.4-19 Comparison of Rear Wall close to Rear Suppor in Lower Compartment in the CFD Model in Section A.4.4.2.2 and the Updated Model of HSM-MX in Section A.4.5 ................................................................................... A.4-98 Figure A.4-20 Comparison of Front Retractable Roller Tray Designs in Upper and Lower Compartments in the CFD Model in Section A.4.4.2.2 and the Updated Model of HSM-MX in Section A.4.5 ........................................... A.4-99 Figure A.4-21 Temperature Profiles for Updated HSM-MX loaded with EOS-37PTH DSC at Bounding Normal Hot Storage Condition (Load Case 1e-S) ...... A.4-100 Figure A.4-22 Temperature Profiles for Updated HSM-MX loaded with EOS-37PTH DSC at Off-Normal Hot Storage Condition (Load Case 2-S) .................. A.4-103 Figure A.4-23 Temperature Profiles for Updated HSM-MX loaded with EOS-37PTH DSC at Accident Blocked Inlet Vents Storage Condition for 32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br /> (Load Case 3-S) ........................................................................................ A.4-106 Figure A.4-24 Streamlines of Airflow inside the HSM-MX Cavity for Normal Hot Storage Condition (Load Case 1e-S) ........................................................ A.4-109 Figure A.4-25 Temperature Profiles for Updated HSM-MX loaded with EOS-37PTH DSC at Bounding Normal Hot Storage Condition (Load Case 1e-S for HLZC 8) .................................................................................................... A.4-110 Figure A.4-26 Temperature Profiles for Updated HSM-MX loaded with EOS-37PTH DSC at Bounding Normal Hot Storage Condition (Load Case 1e-S for HLZC 9) .................................................................................................... A.4-113 Figure A.4-27 Comparison of Designs and Boundary Conditions used in Periodic and Symmetric Models of the HSM-MX in Section A.4.5.7.1 ....................... A.4-116 Figure A.4-28 CFD Model for End Unit HSM-MX with EOS-37PTH DSC Loaded in Lower Compartment ................................................................................. A.4-117 Figure A.4-28a Comparison of Designs and Boundary Conditions used in Periodic Model (Load Case 1e-S in Section A.4.5.3) and Full Model (Load Case 1e-S-full in Section A.4.5.7.3) of the HSM-MX ...................................... A.4-118 Figure A.4-28b Temperature Profiles for Updated HSM-MX loaded with Two Full Upper and One Full Lower EOS-37PTH DSCs at Bounding Normal Hot Storage Condition (Load Case 1e-S-full) ................................................. A.4-119 Page A.4-vi Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4 THERMAL EVALUATION The thermal evaluation described in this chapter is applicable to the NUHOMS EOS System that includes EOS-37PTH or EOS-89BTH dry shielded canisters (DSCs) loaded inside the NUHOMS MATRIX (HSM-MX).

A summary of the EOS-37PTH and EOS-89BTH DSC configurations analyzed in this chapter for storage operations in HSM-MX is shown in the Table in Chapter 4 and also below:

Basket Max. Heat Storage DSC Type Assembly HLZC Load Transfer Cask Module Type (kW) 4H 7 50.00 EOS-37PTH 4L/5 8(1) 46.40(2) EOS-TC125/ EOS-TC135 HSM-MX 4L/5 9 37.80 EOS-89BTH 3 3 34.44 EOS-TC125/ EOS-TC108 Note:

(1) Basket Type 5 can only accommodate Intact FAs. Therefore, damaged or Failed FAs allowed per HLZC 8 shall only be loaded in Basket Type 4L.

(2) The maximum decay heat per DSC is limited to 41.8 kW when a damaged or failed FA is loaded The various basket types within the EOS-37PTH DSC and EOS-89BTH DSC are described in Chapter 1, Section 1.1 and Appendix 4.9.6, Section 4.9.6.1.1.

Descriptions of the detailed analyses performed for normal, off-normal, and hypothetical accident conditions are provided in Section A.4.4 for storage operations.

Transfer operations for the EOS-37PTH DSC with HLZCs 7 through 9 are presented in Section 4.9.6.2. Transfer operations for the EOS-89BTH DSC with HLZC 3 are presented in Section 4.5.6.

In order to accommodate lessons learned from the mockup development, the original HSM-MX design has been slightly revised for improved fabricability. Section A.4.5 evaluates the thermal performance of the updated HSM-MX with the EOS-37PTH and EOS-89BTH DSCs under the bounding normal, off-normal, and accident storage conditions.

Page A.4-1 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.1 Discussion of Decay Heat Removal System Chapter 4, Section 4.1 provides a detailed description of the decay heat removal system within the EOS-37PTH and EOS-89BTH DSCs during storage operations in the EOS-HSM. The decay heat removal system described for storage operations in theEOS-HSM is also applicable for storage operations in the HSM-MX.

Similar to the EOS-HSM described in Chapter 4, Section 4.1, no instrumentation is required to monitor the thermal performance if daily visual inspections of the air inlet and outlet vents are performed. However, in lieu of the daily visual inspections, a direct measurement of the HSM-MX temperature or any other means that would provide an indication of the thermal performance may be used for monitoring in accordance with requirements in Technical Specifications [A.4-13].

Page A.4-2 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.2 Material and Design Limits To establish the heat removal capability, several thermal design criteria are established for the NUHOMS EOS System.

Design criteria for the EOS-37PTH and EOS-89BTH DSCs are identical to those described in Chapter 4, Section 4.2.

For normal and off-normal conditions, the maximum concrete temperature limit is 300 °F, as noted in Section 3.5.1.2 of [A.4-1]. For the accident conditions, if the concrete temperature exceeds the short-term limit of 350 °F noted in Appendix E.4 of ACI 349-06 [A.4-4], concrete testing will be performed, as described in Chapter A.8, Section A.8.2.1.3.

A.4.2.1 Summary of Thermal Properties of Materials The thermal properties of the materials used in the thermal evaluation for Type 4H baskets are the same as those specified in Chapter 4, Section 4.2.1. The basket material properties for Type 4L/5 baskets are discussed in Appendix 4.9.6, Section 4.9.6.1.1.

Page A.4-3 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.3 Thermal Loads and Environmental Conditions For storage operations in the HSM-MX, the maximum temperature is 100 °F for normal storage conditions. A daily average ambient temperature of 90 °F is used in the evaluations, corresponding to a daily maximum temperature of 100 °F for the normal hot storage conditions as discussed in Chapter 4, Section 4.3.

Off-normal ambient temperature is considered in the range of - 40 °F to 117 °F. A daily average ambient temperature of 103 °F is used in the evaluations, corresponding to a daily maximum temperature of 117 °F for the off-normal hot and hypothetical accident storage conditions, as discussed in Chapter 4, Section 4.3. Ambient temperatures of -20 F and -40 F are considered for the normal and off-normal cold storage conditions, respectively.

The HSM-MX is located outdoors and is exposed to the environment. Wind is a normal environment variable that varies frequently both in direction and magnitude.

For the HSM-MX, low speed wind in the range of 0 to 15 mph is considered for normal storage conditions based on the discussion in Section 2.5 of NUREG-2174

[A.4-2].

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.4 Thermal Evaluation for Storage This section provides an evaluation of the thermal performance of the HSM-MX loaded with the EOS-37PTH DSC for normal, off-normal, and hypothetical accident conditions.

Sections A.4.4.1 through A.4.4.3 present the evaluation for EOS-37PTH DSC with Basket Type 4H and a maximum heat load of 50 kW per HLZC 7 in the HSM-MX. A detailed description of Basket Type 4H is presented in Chapter 1, Section 1.1, Chapter 4, and Appendix 4.9.6, Section 4.9.6.1.1.

Within the HSM-MX, the maximum allowable heat loads differ between the upper and the lower compartments for the same DSC. For an EOS-37PTH DSC with Basket Type 4H, the maximum allowable heat loads in the upper and lower compartments are 41.8 kW and 50 kW, respectively.

Section A.4.4.1 and Section A.4.4.2 present a description of the loading cases and the computational fluid dynamics (CFD) model used for the thermal evaluation of the EOS-37PTH during storage in the HSM-MX, respectively.

Section A.4.4.3 presents the results of the thermal evaluation for the EOS-37PTH DSC with Basket Type 4H during storage operations in the HSM-MX per HLZC 7.

Sections A.4.4.3.1, A.4.4.3.2, and A.4.4.3.3 discuss the normal, off-normal, and hypothetical accident conditions of storage, respectively.

Section A.4.4.4 presents the thermal evaluation of the EOS-37PTH DSC with Basket Type 4L/5 during storage operations in the HSM-MX per HLZCs 8 and 9. A description of Basket Type 4L/5 for the EOS-37PTH DSC is presented in Chapter 1, Section 1.1, Chapter 4, and Appendix 4.9.6, Section 4.9.6.1.1.

EOS-37PTH DSC with Basket Type 4L/5 has a maximum heat load of 46.4 and 41.8 kW, respectively, while loaded in the lower and upper compartments of the HSM-MX.

Section A.4.4.5 presents the qualification of the EOS-89BTH DSC with a maximum heat load of 34.44 kW in the HSM-MX.

Page A.4-5 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Proprietary Information on Pages A.4-6 through A.4-17 Withheld Pursuant to 10 CFR 2.390 Page A.4-6 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.4.3.1.2 Temperature Calculations The maximum temperatures of fuel cladding and concrete of the HSM-MX loaded with the EOS-37PTH DSC for normal storage conditions (LCs 1a through 1e) are summarized in Table A.4-2.

The maximum temperatures of various components of the HSM-MX loaded with the EOS-37PTH DSC for the bounding normal storage condition (LC 1e) are summarized in Table A.4-3. The average temperatures of key components of the HSM-MX loaded with the EOS-37PTH DSC for the bounding normal storage condition (LC 1e) are summarized in Table A.4-4.

Typical temperature plots for the key components in the HSM-MX loaded with the EOS-37PTH DSC are shown in Figure A.4-9 for the bounding normal hot condition.

A.4.4.3.1.3 Airflow Calculations The streamlines for the airflow inside the HSM-MX loaded with the EOS-37PTH DSC under normal hot storage condition are shown in Figure A.4-13. Cool air enters into the HSM-MX from the inlet, absorbs the heat from the EOS-37PTH DSC, and leaves the HSM-MX through the outlet with higher temperatures. Table A.4-6 summarizes the air temperatures and mass flow rates at the inlet and outlet for the quiescent normal condition of storage.

A.4.4.3.1.4 GCI Calculation A.4.4.3.2 Off-Normal Conditions of Storage A.4.4.3.2.1 Temperature Calculations The maximum temperatures of fuel cladding and concrete of the HSM-MX loaded with the EOS-37PTH DSC for off-normal storage conditions (LC 2) are summarized in Table A.4-2.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The maximum temperatures of various components of the HSM-MX loaded with the EOS-37PTH DSC for off-normal storage conditions (LC 2) are summarized in Table A.4-3. The average temperatures of key components of the HSM-MX loaded with the EOS-37PTH DSC for off-normal storage condition (LC 2) are summarized in Table A.4-4.

Typical temperature plots for the key components in the HSM-MX loaded with the EOS-37PTH DSC are shown in Figure A.4-10 for off-normal hot conditions.

The minimum temperatures for fuel cladding and basket assembly components assuming no credit for decay heat for off-normal cold storage condition is -40 °F. All materials can be subjected to a minimum environment temperature of -40 °F without any adverse effects.

A.4.4.3.2.2 Airflow Calculations Table A.4-6 summarizes the air temperatures and mass flow rates at the inlet and outlet for LC 2 for off-normal condition of storage.

A.4.4.3.3 Hypothetical Accident Conditions of Storage A.4.4.3.3.1 Temperature Calculations The maximum temperatures of fuel cladding and concrete of the HSM-MX loaded with the EOS-37PTH DSC for hypothetical accident condition of storage (LC 3) are summarized in Table A.4-2.

The maximum temperatures of various components of the HSM-MX loaded with the EOS-37PTH DSC for hypothetical accident condition of storage (LC 3) are summarized in Table A.4-3. The average temperatures of key components of the HSM-MX loaded with the EOS-37PTH DSC for hypothetical accident condition of storage (LC 3) are summarized in Table A.4-4. The values listed in Table A.4-3 and Table A.4-4 for LC 3 are based on transient simulation results at 32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br />.

Typical temperature plots for the key components in the HSM-MX loaded with the EOS-37PTH DSC are shown in Figure A.4-11 for hypothetical accident conditions.

For the accident blocked vent condition, the time histories of the maximum and average temperatures for the key components are shown in Figure A.4-12. All the temperatures increase steadily during the 32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br /> of the blocked vent event.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.4.3.4 Internal Pressure Chapter 4, Section 4.7.1 calculates the maximum internal pressure of the EOS-37PTH DSC during storage in the EOS-HSM and transfer in EOS-TC125/135/108. For the EOS-37PTH DSC during storage in HSM-MX, the average gas temperature in the DSC cavity is computed using the same approach presented in Chapter 4, Section 4.7.1.2 and listed in Table A.4-7. As shown in Table A.4-7, the average helium temperatures determined for the EOS-37PTH DSC in HSM-MX with HLZC 7 are lower than the temperatures determined for HLZCs 1 through 3. Therefore, the maximum internal pressures in Chapter 4, Table 4-45 remain bounding for HLZC 7 under normal, off-normal, and accident storage conditions, respectively.

A.4.4.3.5 Impact of Design Changes The original HSM-MX design has been slightly revised for improved fabricability as described in Section A.4.5.1. Detailed thermal evaluations for the storage in the updated HSM-MX are presented in Section A.4.5. This section evaluates the discrepancy of the original HSM-MX and the thermal model in Section A.4.4.2.2. The evaluation in this section is obsolete and no longer applicable.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Proprietary Information on This Page Withheld Pursuant to 10 CFR 2.390 Page A.4-21 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.4.4 EOS-37PTH DSC with Basket Type 4L/5 - Storage in HSM-MX This section presents the thermal evaluation of the EOS-37PTH DSC with Basket Type 4L/5 during storage operations in the HSM-MX. A description of Basket Type 4L/5 for the EOS-37PTH DSC is presented in Chapter 1, Section 1.1 and Appendix 4.9.6, Section 4.9.6.1.1.

This evaluation considers HLZC 8 with a maximum heat load of 46.4 kW and HLZC 9 with a maximum heat load of 37.8 kW. HLZC 8 and HLZC 9 are shown in Figure 1H and Figure 1I of the Technical Specifications [A.4-13], respectively.

HLZC 8 can accommodate either damaged or failed FAs along with intact FAs but not both. In addition, when damaged or failed FAs are loaded per HLZC 8, the maximum heat load is limited to 41.8 kW per DSC. As discussed in Chapter 1, Section 1.1, damaged/failed FAs shall only be loaded in the EOS-37PTH DSC with Basket Type 4L.

EOS-37PTH DSC with Basket Type 4L/5 has a maximum heat load of 46.4 kW while loaded in the lower compartment of the HSM-MX. The maximum heat load for the EOS-37PTH DSC with Basket Type 4L/5 while loaded in the upper compartment of the HSM-MX is 41.8 kW.

Utilizing these new HLZCs, this section evaluates the thermal performance of the HSM-MX loaded with the EOS-37PTH DSC for normal, off-normal, and accident conditions.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Proprietary Information on Pages A.4-23 and A.4-24 Withheld Pursuant to 10 CFR 2.390 Page A.4-23 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.4.4.2 EOS-37PTH DSC with Basket Type 4L/5 - Thermal Model for Storage in HSM-MX To evaluate the thermal performance of the EOS-37PTH DSC with Basket Type 4L/5 based on HLZCs 8 and 9 during storage operations in HSM-MX, the thermal model from Section A.4.4.2 is modified to simulate LCs described in Section A.4.4.4.1. The modifications in the LCs described in Section A.4.4.4.1 are limited to the changes in material properties of the basket components as described in Appendix 4.9.6, Section 4.9.6.1.1, and heat generation rates based on the new HLZCs, but no changes are considered to the mesh.

A.4.4.4.3 EOS-37PTH DSC with Basket Type 4L/5 for HLZC 8 and 9 -Storage Evaluation Table A.4-9 and Table A.4-10 present the maximum temperatures of fuel cladding and key components of the EOS-37PTH DSC with Basket Type 4L/5 loaded in the HSM-MX based on HLZCs 8 and 9 during storage operations.

Table A.4-11 presents the average temperatures of fuel cladding and key components of the EOS-37PTH DSC with Basket Type 4L/5 loaded in the HSM-MX based on HLZCs 8 and 9 during storage operations.

Figure A.4-14 and Figure A.4-15 present the temperature profiles of key components in the HSM-MX loaded with the EOS-37PTH DSC for HLZCs 8 and 9, respectively.

Comparison with HLZC 7 Table A.4-12 presents a comparison of the maximum temperatures for HLZCs 8 and 9 with the bounding design basis values from HLZC 7. As shown in the comparison, the maximum temperatures determined for HLZC 7 with 50 kW, remain bounding for HLZCs 8 and 9.

Similar to the normal condition, the maximum temperatures during off-normal and accident storage conditions for HLZCs 8 or 9 will also remain bounded by HLZC 7.

Therefore, no further evaluation is required for off-normal and accident storage condition with HLZCs 8 and 9.

Based on this discussion, all design criteria are satisfied for storage of the EOS-37PTH DSC with HLZCs 8 or 9 in the HSM-MX.

Page A.4-25 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Proprietary Information on Pages A.4-26 through A.4-28 Withheld Pursuant to 10 CFR 2.390 Page A.4-26 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.5.4 EOS-37PTH DSC with Basket Type 4H - Storage in Updated HSM-MX A.4.5.4.1 Convergence of the CFD Model A.4.5.4.2 Temperature Calculations The maximum temperatures of fuel cladding and concrete of the updated HSM-MX loaded with the EOS-37PTH DSC for the bounding normal, off-normal, and accident storage conditions are summarized in Table A.4-16.

The maximum temperatures of various components of the HSM-MX loaded with the EOS-37PTH DSC for the bounding normal, off-normal, and accident storage conditions are summarized in Table A.4-17. The average temperatures of key components of the HSM-MX loaded with the EOS-37PTH DSC for the bounding normal, off-normal, and accident storage conditions are summarized in Table A.4-18.

Typical temperature plots for the key components in the HSM-MX loaded with the EOS-37PTH DSC are shown inFigure A.4-21, Figure A.4-22, andFigure A.4-23, respectively, for the bounding normal hot, off-normal hot, and accident conditions.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.5.4.3 Airflow Calculations The streamlines for the airflow inside the updated HSM-MX loaded with the EOS-37PTH DSC under normal hot storage condition are shown in Figure A.4-24.

Cool air enters into the HSM-MX from the inlet, absorbs the heat from the EOS-37PTH DSC, and leaves the HSM-MX through the outlet with higher temperatures. Table A.4-20 summarizes the air temperatures and mass flow rates at the inlet and outlet for the normal and off-normal hot conditions of storage.

A.4.5.4.4 GCI Calculation A.4.5.4.5 Internal Pressure Chapter 4, Section 4.7.1 calculates the maximum internal pressure of the EOS-37PTH DSC during storage in the EOS-HSM and transfer in EOS-TC125/135/108. For the EOS-37PTH DSC during storage in the updated HSM-MX, the average gas temperature in the DSC cavity is computed using the same approach presented in Chapter 4, Section 4.7.1.2 and listed in Table A.4-21. As shown in Table A.4-21, the average helium temperatures determined for the EOS-37PTH DSC in the updated HSM-MX with HLZC 7 are lower than the temperatures determined for HLZCs 1 through 3. Therefore, the maximum internal pressures in Chapter 4, Table 4-45 remain bounding for HLZC 7 under normal, off-normal, and accident storage conditions, respectively.

Page A.4-30 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.5.5 EOS-37PTH DSC with Basket Type 4L/5 - Storage in Updated HSM-MX This section presents the thermal evaluation of the EOS-37PTH DSC with Basket Type 4L/5 during storage operations in the updated HSM-MX. This section follows the same methodology as discussed in Section A.4.4.4. The only difference is the design changes that made to HSM-MX as discussed in Section A.4.5.1.

Same as Section A.4.4.4, this evaluation considers HLZC 8 with a maximum heat load of 46.4 kW and HLZC 9 with a maximum heat load of 37.8 kW. HLZCs 8 and 9 are discussed in Section A.4.4.4.

A.4.5.5.1 EOS-37PTH DSC and Basket Type 4L - Description of Load Cases for Storage A.4.5.5.2 EOS-37PTH DSC with Basket Type 4L/5 - Thermal Model for Storage in HSM-MX To evaluate the thermal performance of the EOS-37PTH DSC with Basket Type 4L/5 based on HLZCs 8 and 9 during storage operations in the updated HSM-MX, the thermal model from Section A.4.5.3 is modified to simulate LCs described in Section A.4.5.5.1. The modifications in the LCs described in Section A.4.5.5.1 are limited to the changes in material properties of the basket components as described in Appendix 4.9.6, Section 4.9.6.1.1, and heat generation rates based on the new HLZCs, but no changes are considered to the mesh.

A.4.5.5.3 EOS-37PTH DSC with Basket Type 4L/5 for HLZCs 8 and 9 -Storage Evaluation Figure A.4-23and Figure A.4-24 present the maximum temperatures of fuel cladding and key components of the EOS-37PTH DSC with Basket Type 4L/5 loaded in the updated HSM-MX based on HLZCs 8 and 9 during storage operations.

Page A.4-31 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.4-25 presents the average temperatures of fuel cladding and key components of the EOS-37PTH DSC with Basket Type 4L/5 loaded in the updated HSM-MX based on HLZCs 8 and 9 during storage operations.

Figure A.4-25 and Figure A.4-26 present the temperature profiles of key components in the HSM-MX loaded with the EOS-37PTH DSC for HLZCs 8 and 9, respectively.

Comparison with HLZC 7 Table A.4-26 presents a comparison of the maximum temperatures for HLZCs 8 and 9 with the bounding design basis values from HLZC 7. As shown in the comparison, the majority of the maximum component temperatures determined for HLZC 7 with 50 kW remain bounding for HLZCs 8 and 9. The maximum temperature of the heat shield in the upper compartment for HLZC 8 is slightly higher (2 °F) than that for HLZC 7.

Similar to the normal condition, the maximum temperatures during off-normal and accident storage conditions for HLZCs 8 or 9 will also remain bounded by HLZC 7.

Therefore, no further evaluation is required for off-normal and accident storage condition with HLZCs 8 and 9.

Based on this discussion, all design criteria are satisfied for storage of the EOS-37PTH DSC with HLZCs 8 or 9 in the updated HSM-MX.

A.4.5.6 EOS-89BTH DSC with Basket Type 3 - Storage in Updated HSM-MX Page A.4-32 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Proprietary Information on Pages A.4-33 through A.4-37 Withheld Pursuant to 10 CFR 2.390 Page A.4-33 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.4.6 References A.4-1 NUREG-1536, Standard Review Plan for Spent Fuel Dry Cask Storage Systems at a General License Facility, Revision 1, U.S. Nuclear Regulatory Commission, July 2010.

A.4-2 NUREG-2174, Impact of Variation in Environmental Conditions on the Thermal Performance of Dry Storage Casks - Final Report, U.S. Nuclear Regulatory Commission, March 2016.

A.4-3 J.M. Cuta, U.P. Jenquin, and M.A. McKinnon, Evaluation of Effect of Fuel Assembly Loading Patterns on Thermal and Shielding Performance of a Spent Fuel Storage/Transportation Cask, , PNNL-13583, Pacific Northwest National Laboratory, November 2001.

A.4-4 ACI 349-06, Code Requirements for Nuclear Safety Related Concrete Structures American Concrete Institute.

A.4-5 ANSYS FLUENT, ANSYS FLUENT Users Guide, Version 17.1, ANSYS, Inc.

A.4-6 ANSYS ICEM CFD, Version 17.1, ANSYS, Inc.

A.4-7 NUREG-2152, Computational Fluid Dynamics Best Practice Guidelines for Dry Cask Applications, U.S. Nuclear Regulatory Commission, March 2013.

A.4-8 American Society of Mechanical Engineers, Standard for Verification and Validation in Computational Fluid Dynamics and Heat Transfer, ASME V&V 20-2009, November 30th, 2009.

A.4-9 I. E. Idelchik, Handbook of Hydraulic Resistance, 3rd Edition, Begell House, Inc.,

1996.

A.4-10 A Zigh, J Solis, Computational Fluid Dynamics Best Practice Guidelines in Analysis of Dry Storage Cask, WM2008 Conference, Phoenix, AZ, February 24-28, 2008.

A.4-11 ASHRAE Handbook, Fundamentals, SI Edition, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., 1997.

A.4-12 P. J. Roache, Quantification of Uncertainty in Computational Fluid Dynamics, Annual Review of Fluid Mechanics, Vol. 29, 123-160, 1997.

A.4-13 CoC 1042 Appendix A, NUHOMS EOS System Generic Technical Specifications, Amendment 1.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.4-1 EOS-37PTH DSC in HSM-MX, Design Load Cases for Storage Conditions with HLZC 7 Ambient Operating Load Case Description Mesh Temperature Condition

(°F) 1a 1b 1c Base Normal 100 (1) 1d 1e 1f Fine 2 Off-Normal Base 117 (1) 3 (2) Accident Base 117 (1)

Notes:

(1) Daily average temperatures are used as noted in Section A.4.3.

(2) Initial temperatures are taken from steady-state results of Load Case 2.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.4-2 Maximum Fuel Cladding and Concrete Temperatures for Storage Conditions of EOS-37PTH DSC in HSM-MX with HLZC 7 Concrete Max Fuel Cladding Temperature (°F)

Load Temperature (°F)

Description Case (1) Upper Lower Limit Maximum(4) Limit Compartment Compartment 1a 641 686 246 1b 651 684 245 1c 660 690 250 (2) 752 1d 671 699 260 300(2) 1e 676 708 273 1f 676 707 273 2 653 696 263 (2) 1058 3 724 777 371 500(3)

Notes:

(1) See Table A.4-1 for the description of the LCs.

(2) The temperature limits are from NUREG-1536 [A.4-1].

(3) The temperature limit for concrete at accident condition is 500 °F. The maximum concrete temperature for accident conditions is above the 350 °F limit given in ACI 349-06 [A.4-4]. Testing will be performed, as described in Chapter A.8, Section A.8.2.1.3.

(4) According to the sensitivity study in Section A.4.4.3.5, the maximum concrete temperatures are added by 9 °F for conservatism.

Page A.4-40 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Proprietary Information on Pages A.4-41 through A.4-46 Withheld Pursuant to 10 CFR 2.390 Page A.4-41 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.4-9 Maximum Fuel Cladding and Concrete Temperatures for Storage Conditions of EOS-37PTH DSC in HSM-MX with HLZCs 8 and 9 Concrete Max Fuel Cladding Temperature (°F)

Load Temperature (°F)

Case (1) Upper Lower Limit Maximum(4) Limit Compartment Compartment LC1e for 679 698 262 HLZC 8 LC1e for 752(2) 300(2)

HLZC 675 698 262 9(3)

Notes:

(1) See Table A.4-8 for the description of the LCs.

(2) The temperature limits are from NUREG-1536 [A.4-1].

(3) DSC in the upper compartment is modeled per HLZC 9, whereas DSC in the lower compartment is modeled per HLZC 8 as discussed in Section A.4.4.4.1.

(4) According to the sensitivity study in Section A.4.4.3.5, the maximum concrete temperatures are added by 9 °F for conservatism.

Page A.4-47 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Proprietary Information on Pages A.4-48 through A.4-51 Withheld Pursuant to 10 CFR 2.390 Page A.4-48 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.4-14 EOS-37PTH DSC in Updated HSM-MX, Design Load Cases for Storage Conditions with HLZC 7 Ambient Operating Load Case Description Mesh Temperature Condition

(°F) 1e-S Base Normal 100 (1) 1f-S Fine 2-S Off-Normal Base 117 (1) 3-S (2) Accident Base 117 (1)

Notes:

(1) Daily average temperatures are used as noted in Section A.4.3.

(2) Initial temperatures are taken from steady-state results of Load Case 2-S.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Proprietary Information on This Page Withheld Pursuant to 10 CFR 2.390 Page A.4-53 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.4-16 Maximum Fuel Cladding and Concrete Temperatures for Storage Conditions of EOS-37PTH DSC in Updated HSM-MX with HLZC 7 Concrete Temperature Max Fuel Cladding Temperature (°F)

Load (°F)

Description Case (1) Lower Upper Compartment Limit Maximum(4) Limit Compartment 1e 676 708 264 752(2) 1e-S 680 704 261 4 -4 -3 2 653 696 254 300(2) 2-S 648 685 245

-5 -11 -9 1058(2) 3 724 777 362 3-S 699 770 355 500(3)

-25 -7 -7 Notes:

(1) See Table A.4-1 and Table A.4-14 for the description of the LCs.

(2) The temperature limits are from NUREG-1536 [A.4-1].

(3) The temperature limit for concrete at accident condition is 500 °F. The maximum concrete temperature for accident conditions is above the 350 °F limit given in ACI 349-06 [A.4-4]. Testing will be performed, as described in Chapter A.8, Section A.8.2.1.3.

Page A.4-54 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Proprietary Information on Pages A.4-55 through A.4-59 Withheld Pursuant to 10 CFR 2.390 Page A.4-55 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.4-23 Maximum Fuel Cladding and Concrete Temperatures for Storage Conditions of EOS-37PTH DSC in Updated HSM-MX with HLZCs 8 and 9 Concrete Temperature Max Fuel Cladding Temperature (°F)

(°F)

Load Case (1) Upper Lower Limit Maximum Limit Compartment Compartment LC 1e-S for 682 694 256 HLZC 8 752(2) 300(2)

LC 1e-S for 677 694 252 HLZC 9(3)

Notes:

(1) See Table A.4-22 for the description of the LCs.

(2) The temperature limits are from NUREG-1536 [A.4-1].

(3) DSC in the upper compartment is modeled per HLZC 9, whereas DSC in the lower compartment is modeled per HLZC 8 as discussed in Section A.4.4.4.1.

Page A.4-60 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Proprietary Information on Pages A.4-61 through A.4-121 Withheld Pursuant to 10 CFR 2.390 Page A.4-61 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.5 CONFINEMENT There is no change to the confinement assessment documented in Chapter 5 due to the addition of the NUHOMS MATRIX.

Page A.5-1 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.6 SHIELDING EVALUATION Table of Contents A.6 SHIELDING EVALUATION ...................................................................................... A.6-1 A.6.1 Discussions and Results ................................................................................. A.6-2 A.6.2 Source Specification ....................................................................................... A.6-4 A.6.2.1 Computer Programs .......................................................................... A.6-4 A.6.2.2 PWR and BWR Source Terms .......................................................... A.6-4 A.6.2.3 Axial Source Distributions and Subcritical Neutron Multiplication.................................................................................... A.6-4 A.6.2.4 Control Components ......................................................................... A.6-4 A.6.2.5 Blended Low Enriched Uranium Fuel .............................................. A.6-4 A.6.2.6 Reconstituted Fuel ............................................................................ A.6-4 A.6.2.7 Irradiation Gases ............................................................................... A.6-4 A.6.3 Model Specification ........................................................................................ A.6-5 A.6.3.1 Material Properties ............................................................................ A.6-5 A.6.3.2 MCNP Model Geometry for the EOS-TC ........................................ A.6-5 A.6.3.3 MCNP Model Geometry for the HSM-MX ...................................... A.6-5 A.6.4 Shielding Analysis .......................................................................................... A.6-8 A.6.4.1 Computer Codes................................................................................ A.6-8 A.6.4.2 Flux-to-Dose Rate Conversion ......................................................... A.6-8 A.6.4.3 EOS-TC Dose Rates ......................................................................... A.6-8 A.6.4.4 HSM-MX Dose Rates ....................................................................... A.6-8 A.6.5 Supplemental Information .......................................................................... A.6-11 A.6.5.1 References ....................................................................................... A.6-11 Page A.6-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Tables Table A.6-1 HSM-MX Key As-Modeled Dimensions (Inches) ........................................ A.6-12 Table A.6-2 HSM-MX Dose Rate Results (mrem/hr) ....................................................... A.6-13 Table A.6-3 HSM-MX Primary Gamma Average Fluxes and Dose Rates, Normal Conditions ...................................................................................................... A.6-14 Table A.6-4 HSM-MX Secondary Gamma Average Fluxes and Dose Rates, Normal Conditions ...................................................................................................... A.6-16 Table A.6-5 HSM-MX Neutron Average Fluxes and Dose Rates, Normal Conditions .... A.6-18 Table A.6-6 HSM-MX Primary Gamma Flux from the EOS-89BTH DSC, Accident Conditions ...................................................................................................... A.6-19 Table A.6-7 HSM-MX Secondary Gamma Flux from the EOS-89BTH DSC, Accident Conditions ...................................................................................................... A.6-21 Table A.6-8 HSM-MX Neutron Flux from the EOS-89BTH DSC, Accident Conditions A.6-23 Page A.6-ii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Figures Figure A.6-1 HSM-MX MCNP Single-Reflection Model, X-Y View ............................... A.6-24 Figure A.6-2 HSM-MX MCNP Single-Reflection Model, Z-Y View through Lower Compartment.................................................................................................. A.6-25 Figure A.6-3 HSM-MX MCNP Single-Reflection Model, Z-Y View through Upper Compartment.................................................................................................. A.6-26 Figure A.6-4 HSM-MX MCNP Single-Reflection Model, X-Z Views .............................. A.6-27 Figure A.6-5 HSM-MX MCNP Double-Reflection Model................................................. A.6-28 Figure A.6-6 HSM-MX MCNP Triple-Reflection Model................................................... A.6-29 Figure A.6-7 Dose Reduction Hardware ............................................................................. A.6-30 Figure A.6-8 HSM-MX MCNP Array Expansion Model ................................................... A.6-31 Figure A.6-9 HSM-MX MCNP Array Expansion Model, Accident Configuration ........... A.6-32 Figure A.6-10 HSM-MX Key Dose Rate Results ................................................................. A.6-33 Page A.6-iii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.6 SHIELDING EVALUATION The radiation shielding evaluation for the NUHOMS EOS System for transfer of an EOS dry shielded canister (EOS-DSC) and storage in an EOS horizontal storage module (EOS-HSM) is documented in Chapter 6. The following radiation shielding evaluation addresses the storage of an EOS-DSC in a NUHOMS MATRIX (HSM-MX). Detailed three-dimensional (3D) dose rate evaluations are performed to determine the dose rate fields around an HSM-MX. These near-field dose rates are used as input to the dose assessment documented in Chapter A.11.

The methodology, source terms, and dose rates presented in this chapter are developed to be reasonably bounding for general licensee implementation of the EOS System.

These results may be used in lieu of near-field evaluations by the general licensee, although the inputs utilized in this chapter should be evaluated for applicability by each site. Site-specific HSM-MX near-field evaluations may be performed by the general licensee to modify key input parameters.

Site dose evaluations for the HSM-MX under normal, off-normal, and accident conditions are documented in Chapter A.11, based on the near-field HSM-MX results presented in this chapter. Because the arrangement and the distance to the site boundary is site-specific, compliance with 10 CFR 72.104 and 10 CFR 72.106 for the HSM-MX can only be demonstrated using a site-specific evaluation. Inputs for the site dose evaluations developed in the current chapter may be directly used as input to a site-specific dose evaluation by the general licensee.

Page A.6-1 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.6.1 Discussions and Results The following is a summary of the methodology and results of the shielding analysis of HSM-MX. More detailed information is presented in the body of the chapter.

Source Terms For the HSM-MX, the DSC in the lower compartment is limited to 50.0 kW, while the DSC in the upper compartment is limited to 41.8 kW. PWR heat load zoning configurations (HLZC) 7, 8, and 9 are used with the HSM-MX, as well as boiling water reactor (BWR) HLZC 3. The HLZCs are defined in the Technical Specifications, Figure 1G through Figure 2 [A.6-2].

In the EOS-HSM analysis documented in Chapter 6, Section 6.4.4, it is demonstrated that the vent dose rates are approximately 50% larger for the EOS-89BTH DSC compared to the EOS-37PTH DSC. Because the EOS-HSM and HSM-MX both feature thick concrete shielding with vents and the maximum dose rates occur at the vents, the EOS-89BTH DSC also bounds the EOS-37PTH DSC in the HSM-MX.

Therefore, detailed dose rate evaluations are performed only for the EOS-89BTH DSC.

Detailed EOS-89BTH DSC source terms are developed for the EOS-HSM analysis in Section 6.2 for HLZC 1. These source terms are used without modification in the HSM-MX analysis in both the lower and upper compartments. BWR HLZC 1, which has a heat load of 43.6 kW, is conservatively modeled in the upper HSM-MX compartment, although the upper compartment is limited to a lower decay heat. Note that BWR HLZC 1 is not an allowed content for the HSM-MX, as the only BWR HLZC authorized for storage in the HSM-MX is HLZC 3. Utilizing HLZC 1 sources in the HSM-MX adds a large degree of conservatism in the dose rate results, because HLZC 1 accepts stronger sources compared to HLZC 3.

Dose Rates The EOS-37PTH and EOS-89BTH DSCs are transferred to the HSM-MX using the EOS-TC. The EOS-TC dose rates provided in Chapter 6 are applicable to transfer to the HSM-MX. Therefore, the dose rates reported in this appendix are limited to the HSM-MX.

Page A.6-2 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The Monte Carlo transport code, MCNP5 [A.6-1], is used to compute dose fields around the HSM-MX using detailed 3D models. [

] A summary of the limiting HSM-MX dose rates is provided in Table A.6-2. The dose rate excluding the contribution from the inlet and outlet vents is small, as the dose rates are due primarily to streaming from the vents. The maximum dose rates at the inlet and outlet vents are 1,470 mrem/hr and 993 mrem/hr, respectively. The average dose rate on the front face of the module is 47.0 mrem/hr, and the average dose rate on the roof above the vent covers is 141 mrem/hr. The dose rate at the door centerline is 1.97 mrem/hr. The fluxes and dose rates on the surface of the HSM-MX are used as input to a generic site dose evaluation documented in Chapter A.11.

The shielding effectiveness of the HSM-MX is not affected by any off-normal events.

The following geometry changes may occur in an accident:

Loss of outlet vent covers Loss of dose reduction hardware Damage to interior walls due to missile impact when the HSM-MX is in the construction joint expansion configuration with the removable end shield wall absent 10 CFR 72.106 limits the dose to an individual at the site boundary to be less than 5 rem due to an accident. Monte Carlo N-Particle (MCNP) cases are developed for the HSM-MX, in which all vent covers and dose reduction hardware are absent, which is not credible. An MCNP case is also developed for a missile impact when the HSM-MX is in the construction joint expansion configuration with the removable end shield wall absent. In this configuration, it is conservatively assumed that two interior walls are penetrated. The HSM-MX accident increases the average dose rate on the front, roof, and end of the module to 92.9 mrem/hr, 4,730 mrem/hr, and 425 mrem/hr, respectively. The fluxes and dose rates on the surface of the HSM-MX in an accident condition are used as input to an accident site dose evaluation documented in Chapter A.11.

Page A.6-3 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.6.2 Source Specification Source term information in Section 6.2 is applicable to the HSM-MX evaluation.

A.6.2.1 Computer Programs No change to Section 6.2.1.

A.6.2.2 PWR and BWR Source Terms The EOS-89BTH DSC bounds the EOS-37PTH DSC for storage in the EOS-HSM, see the discussion in Section 6.4.4. Because the EOS-HSM and HSM-MX both feature thick concrete shielding with vents and the maximum dose rates occur at the vents, the EOS-89BTH DSC also bounds the EOS-37PTH DSC in the HSM-MX.

Therefore, detailed HSM-MX dose rate evaluations are performed only for the EOS-89BTH DSC.

Detailed EOS-89BTH DSC source terms are developed for the EOS-HSM analysis in Section 6.2 for HLZC 1. These source terms are provided in Table 6-27 through Table 6-29 and maximize the dose rates at the vents. These source terms are used without modification in the HSM-MX analysis in both the lower and upper compartments.

BWR HLZC 1, which has a heat load of 43.6 kW, is conservatively modeled in the upper HSM-MX compartment, although the upper compartment is limited to 41.8 kW.

Note that BWR HLZC 1 is not an allowed content for the HSM-MX, because the only BWR HLZC authorized for storage in the HSM-MX is HLZC 3. Utilizing HLZC 1 sources in the HSM-MX adds a large degree of conservatism in the dose rate results, because HLZC 1 accepts stronger sources compared to HLZC 3.

A.6.2.3 Axial Source Distributions and Subcritical Neutron Multiplication No change to Section 6.2.3.

A.6.2.4 Control Components No change to Section 6.2.4.

A.6.2.5 Blended Low Enriched Uranium Fuel No change to Section 6.2.5.

A.6.2.6 Reconstituted Fuel No change to Section 6.2.6.

A.6.2.7 Irradiation Gases No change to Section 6.2.7.

Page A.6-4 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.6.3 Model Specification MCNP5 is used to perform detailed 3D near-field dose rate evaluations for the HSM-MX. All relevant details of the EOS-89BTH DSC and HSM-MX are modeled explicitly.

Separate primary gamma and neutron models are developed. The HSM-MX neutron models are run in coupled neutron-photon mode so that the secondary gamma dose rate from (n,) reactions may be computed. The secondary gamma dose rates from the HSM-MX are negligible but are computed for completeness.

The treatment of subcritical neutron multiplication is suppressed in MCNP by using the NONU card. This is done because the fuel assemblies are modeled as fresh fuel and homogenized for simplicity, which would cause inaccurate treatment of subcritical neutron multiplication by MCNP. Subcritical neutron multiplication is accounted for in the neutron source magnitude.

A.6.3.1 Material Properties The HSM-MX models use the same material properties documented in Section 6.3.1 with the exception of the concrete density. Concrete used in the HSM-MX is modeled without steel rebar at a conservatively low density of 138 pcf (2.22 g/cm3) compared to 140 pcf (2.24 g/cm3) for the EOS-HSM.

A.6.3.2 MCNP Model Geometry for the EOS-TC The EOS-TC models documented in Section 6.3.2 are applicable for transfer to the HSM-MX.

A.6.3.3 MCNP Model Geometry for the HSM-MX Detailed HSM-MX MCNP models are developed for an EOS-89BTH DSC in the upper and lower compartments. The EOS-89BTH DSC models developed in Section A.6.3.2 are used without modification in the HSM-MX models. BWR source terms are as described in Section A.6.2.2.

The HSM-MXs are modeled explicitly, including the inlet (front) and outlet (roof) vents. The lower compartment features a single horizontal inlet vent at ground level directly under the DSC, while the upper compartment features two vertical inlet vents that are located between the lower compartments. Key dimensions used to develop the HSM-MX models are summarized in Table A.6-1, and figures illustrating the MCNP models with key features labeled are provided in Figure A.6-1 through Figure A.6-6.

The HSM-MX is a monolithic design of two tiers of DSCs. The length of the monolith is arbitrary and determined by the customer. The roof is integral to the HSM-MX, as well as the end shield walls and the rear shield wall. The monolith may be either a single row or a double row (i.e., back-to-back arrangement).

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The minimum thickness of the roof is 4 feet 2 inches. The minimum thickness of the integral end shield wall is 3 feet 8 inches. The minimum thickness of the optional removable end shield wall is 3 feet. In the single-row design, the thickness of the integral rear shield wall is 3 feet 8 inches. In the back-to-back design, the wall thickness between rows is 2 feet 6 inches.

Air inlet vents are located on the front and air outlet vents are located on the roof.

Because little radiation directly penetrates the thick concrete shielding, essentially all of the dose rate is due to gamma radiation streaming from the vents. Radiation streaming through the outlet vents is mitigated by the use of vent covers, see Figure A.6-1. Under normal and off-normal conditions the vent covers are always in place.

The baseline MCNP configuration features an HSM-MX with a rear shield wall. On the left side (-x direction) an end shield wall is modeled, while on the right side (+x direction) a mirror boundary is modeled at the centerline of the DSC in the upper compartment, see Figure A.6-1 through Figure A.6-4. The length of the DSC is in the z-direction. This configuration is used to compute dose rates and fluxes on the end shield wall.

A second MCNP configuration features mirror boundaries on both the left and right sides of the model through the centerline of the DSCs in the lower compartments, although the rear shield wall is modeled explicitly, see Figure A.6-5. This configuration is used to simulate the interior region of a single row and is used to compute dose rates and fluxes on the rear shield wall.

A third MCNP configuration features mirror boundaries on the left, right, and rear of the model, see Figure A.6-6. This configuration is used to simulate the interior region of a double row (i.e., back-to-back arrangement) and is used to compute front and roof vent dose rates, as well as average front and roof dose rates and fluxes.

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When an HSM-MX is to be expanded in the future, construction may be terminated at a construction joint and a 3 feet thick removable end shield wall is attached. The two complete compartments (one upper and one lower) nearest the end must remain empty when the HSM-MX is loaded, as indicated in Figure A.6-8. This configuration is explicitly modeled to determine the end dose rate when the removable end shield wall is absent. If an array to be expanded terminates at an expansion joint rather than a construction joint, the two compartments (one upper and one lower) nearest the end wall must remain empty. End dose rates for this configuration are bounded by the construction joint option with the end shield wall removed.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 ADVANTG [A.6-3] is used to develop weight windows to accelerate problem convergence for all models.

The average fluxes on the faces of the HSM-MX are used as input to a generic site dose evaluation that is documented in Chapter A.11. These average fluxes are computed on the surface of a box that envelops the HSM-MX model, including the vent covers and door.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.6.4 Shielding Analysis A.6.4.1 Computer Codes MCNP5 v1.40 is used in the shielding analysis [A.6-1]. MCNP5 is a Monte Carlo transport program that allows full 3D modeling of the HSM-MX. Therefore, no geometrical approximations are necessary when developing the shielding models.

A.6.4.2 Flux-to-Dose Rate Conversion No change to Section 6.4.2.

A.6.4.3 EOS-TC Dose Rates No change to Section 6.4.3.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The maximum dose rate at the roof outlet vent is 993 mrem/hr. The maximum dose rate at the lower compartment inlet vent is 1,470 mrem/hr, while the maximum dose rate at the upper compartment inlet vent is 1,350 mrem/hr.

The total dose rate is dominated by primary gammas, while the dose rate from neutrons and secondary gammas is negligible. The bulk shielding of the HSM-MX is very effective in the absence of streaming. The average dose rate on the rear and end (side) shield walls is 0.484 mrem/hr and 0.632 mrem/hr, respectively. The dose rate at the door centerline is 1.97 mrem/hr. These surfaces do not contain streaming paths, although the average rear and end dose rates are computed to the top of the vent covers and include contribution from the roof vents. The average dose rate on the front face of the module is 47.0 mrem/hr, and the average dose rate on the roof above the vent covers is 141 mrem/hr.

Input for Site Dose Evaluation The average dose rate and flux on the surface of the HSM-MX is of interest for use in the generic site dose evaluations. The site dose evaluations are documented in Chapter A.11, although the inputs to the site dose evaluation are obtained from the HSM-MX evaluations described in the current chapter.

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Average fluxes and dose rates on the end, rear, front, and roof of the HSM-MX with the EOS-89BTH DSC are reported in Table A.6-3, Table A.6-4, and Table A.6-5, for primary gamma, secondary gamma, and neutron radiation, respectively. These dose rates and fluxes are applicable to normal and off-normal conditions.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20

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Expansion Considerations As shown in Figure A.6-8, when an array is in the construction joint expansion configuration, the two complete compartments (one upper and one lower) at the end of the module must remain empty. A removable end shield wall is attached. These empty compartments are required to maintain low dose rates when the removable end shield wall is absent during subsequent construction activities. If an array to be expanded terminates at an expansion joint rather than a construction joint, the two compartments (one upper and one lower) nearest the end wall must remain empty.

End dose rates for this configuration are bounded by the construction joint option with the end shield wall removed.

Use of Low-Density Grout for HSM-MX Repair

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.6.5 Supplemental Information A.6.5.1 References A.6-1 Oak Ridge National Laboratory, MCNP/MCNPX - Monte Carlo N-Particle Transport Code System Including MCNP5 1.40 and MCNPX 2.5.0 and Data Libraries, CCC-730, RSICC Computer Code Collection, January 2006.

A.6-2 CoC 1042 Appendix A, NUHOMS EOS System Generic Technical Specifications, Amendment 1.

A.6-3 ADVANTG - An Automated Variance Reduction Parameter Generator, Oak Ridge National Laboratory, August 2015.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Proprietary Information on Pages A.6-12 through A.6-33 Withheld Pursuant to 10 CFR 2.390 Page A.6-12 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.7 CRITICALITY EVALUATION There is no change to the criticality evaluation documented in Chapter 7 due to the addition of the NUHOMS MATRIX.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.8 MATERIALS EVALUATION Table of Contents A.8 MATERIALS EVALUATION .................................................................................... A.8-1 A.8.1 General Information ...................................................................................... A.8-2 A.8.1.1 HSM-MX Materials .......................................................................... A.8-2 A.8.1.2 Environmental Conditions ................................................................ A.8-2 A.8.1.3 Engineering Drawings ...................................................................... A.8-2 A.8.2 Materials Selection ......................................................................................... A.8-3 A.8.2.1 Applicable Codes and Standards and Alternatives ........................... A.8-3 A.8.2.2 Material Properties ............................................................................ A.8-4 A.8.2.3 Materials for ISFSI Sites with Experience of Atmospheric Chloride Corrosion............................................................................ A.8-5 A.8.2.4 Weld Design and Inspection ............................................................. A.8-5 A.8.2.5 Galvanic and Corrosive Reactions .................................................... A.8-6 A.8.2.6 Creep Behavior of Aluminum ........................................................... A.8-6 A.8.2.7 Bolt Applications .............................................................................. A.8-7 A.8.2.8 Protective Coatings and Surface Treatments .................................... A.8-7 A.8.2.9 Neutron Shielding Materials ............................................................. A.8-7 A.8.2.10 Materials for Criticality Control ....................................................... A.8-7 A.8.2.11 Concrete and Reinforcing Steel ........................................................ A.8-7 A.8.2.12 Seals .................................................................................................. A.8-7 A.8.2.13 Low Temperature Ductility of Ferritic Steels ................................... A.8-7 A.8.3 Fuel Cladding ................................................................................................. A.8-8 A.8.4 Prevention of Oxidation Damage During Loading of Fuel ........................ A.8-9 A.8.5 Flammable Gas Generation ........................................................................ A.8-10 A.8.6 DSC Closure Weld Testing ......................................................................... A.8-11 A.8.7 References ..................................................................................................... A.8-12 Page A.8-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Tables Table A.8-1 HSM-MX Materials ....................................................................................... A.8-13 Table A.8-2 Material Properties, ASTM A572 Grade 50 Steel ......................................... A.8-14 Table A.8-3 Material Properties, ASTM A992 Grade 50 .................................................. A.8-15 Table A.8-4 Material Properties, ASTM A588 .................................................................. A.8-16 Page A.8-ii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.8 MATERIALS EVALUATION This chapter only provides the material evaluation for the NUHOMS MATRIX (HSM-MX) in accordance with the guidance outlined in NUREG-1536, Revision 1

[A.8-1]. There are no changes to the materials evaluation of other components in the NUHOMS EOS System in Chapter 8.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.8.1 General Information A.8.1.1 HSM-MX Materials Steel materials employed in the various components of the HSM-MX, particularly those that are relied on for structural integrity, are based on American Society for Testing and Materials (ASTM) and American Society of Mechanical Engineers (ASME) specifications. Horizontal storage module (HSM) concrete is based on American Concrete Institute (ACI) specifications.

A.8.1.2 Environmental Conditions The dry shielded canister (DSC) and NUHOMS MATRIX (HSM-MX) are exposed to the ambient weather conditions at the licensee site for the duration of the licensing period. Depending on the licensee local conditions, the environment may include chloride aerosols, precipitation, and freezing temperatures. The monolith roof, front wall, door, sides, rear (for single row arrays) and shield walls (if applicable) of the HSM-MX concrete are directly exposed to the weather. The HSM-MX interior, and the DSC exterior surfaces are sheltered from direct effects of weather, though moisture and aerosols present in the air pass through the HSM-MX interior via natural convection. Material temperatures of the storage system components are presented in Chapter A.4.

During storage, the interior of the DSC is exposed to an inert helium environment.

The DSC is vacuum-dried and backfilled with helium after loading the fuel and welding the inner top cover plate.

The DSC and TC are unchanged from the NUHOMS EOS System; therefore, there are no changes to the environmental conditions relative to the DSC and TC discussed in Section 8.1.2.

A.8.1.3 Engineering Drawings The drawings for HSM-MX are provided in Chapter A.1, Section A.1.3. The material specification, governing code, and quality category are specified in the parts list for each component.

There are no changes to the EOS-37PTH, EOS-89BTH and TC drawings provided in Chapter 1, Section 1.3.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.8.2 Materials Selection This section discusses the materials used in the HSM-MX components. Table A.8-1 summarizes the materials selected for HSM-MX. Materials utilized in the HSM-MX are largely the same as those used in the EOS-HSM, and the materials for the EOS-DSCs and EOS-TCs have not changed. Therefore, the tables described in Section 8.2 also applicable to HSM-MX. Temperature-dependent mechanical and thermal properties for the materials listed in Table A.8-1 are presented in Table A.8-2 through Table A.8-4.

A.8.2.1 Applicable Codes and Standards and Alternatives A.8.2.1.1 EOS-37PTH and EOS-89BTH DSC No change from Section 8.2.1.1.

A.8.2.1.2 EOS-TC Transfer Cask No change from Section 8.2.1.2.

A.8.2.1.3 HSM-MX Horizontal Storage Module The applicable codes for the HSM-MX are:

Concrete construction per ACI-318-08 [A.8-4].

Concrete Design per ACI-349-06 [A.8-5].

DSC Support design per AISC Manual of Steel Construction [A.8-7].

Cement, aggregate, reinforcing steel, and steel structures conform to ASTM specifications.

The HSM-MX concrete subcomponents are designed and constructed using a specified 28-day compressive strength of 5,000 psi, normal weight concrete. The cement is Type II or Type III Portland cement meeting the requirements of ASTM C150. The concrete aggregate meets the specifications of ASTM C33. The reinforcing steel is ASTM A615 or A706 Gr. 60 deformed bars placed vertically and horizontally at each face of the walls, roof and slabs.

The concrete surface temperature limits criteria are based on the provisions in Section 3.5.1.2 of NUREG-1536, as follows:

If concrete temperatures in general or local areas are at or below 200 °F for normal/off-normal conditions/occurrences, no tests to prove capability at elevated temperatures or reduction of concrete strength are required.

If concrete temperatures, in general, or local areas exceed 200 °F, but do not exceed 300 °F, no tests to prove capability at elevated temperatures or reduction of concrete strength are required if the aggregates have a coefficient of thermal expansion (CTE) no greater than 6x10-6 in/in/°F, or are one of the following materials: limestone, dolomite, marble, basalt, granite, gabbro, or rhyolite.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The above criteria in lieu of the ACI 349-06 requirements do not extend above 300 °F for normal/off-normal conditions and do not modify the ACI 349-06 requirements for accident conditions. Per E.4.2 of ACI 349-06 [A.8-5], the accident conditions or short-term period (i.e., blocked vent accident transient) concrete temperatures are limited to 350 °F. Higher temperatures are allowed per E.4.3 if tests are provided to evaluate the reduction in strength and this reduction is applied to design allowables.

HSM-MX concrete compressive tests are performed on specimens heated to or above that maximum accident temperature for no less than 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br />. HSM-MX concrete temperature testing is performed whenever there is a significant change in the cement, aggregate, or water-cement ratio of the concrete mix design. See Section 5.3 of the Technical Specifications [A.8-17].

Alternatively, per the ACI 349-13 [A.8-10] commentary Section RE.4, the specified 28-day compressive strength can be increased to 7,000 psi for HSM fabrication, in lieu of the above aggregate types or coefficient of thermal expansion requirements, so that any losses in properties (e.g., compressive strength, modulus of elasticity) resulting from long-term thermal exposure will not affect the safety margins based on the specified 5,000 psi compressive strength used in the design evaluations. Additionally, also as indicated in Section RE.4, short, randomly oriented steel fibers may be used to provide increased ductility, dynamic strength, toughness, tensile strength, and improved resistance to spalling. See Section 4.4.4 of the Technical Specifications

[A.8-17].

The rear DSC supports consists of a W6 x 25 structural beam of ASTM A992 Gr.50 material or equivalent built-up I-Beam of ASTM A572 Gr. 50 material coated with an inorganic zinc-rich primer and a high-build epoxy enamel finish. The DSC rests on an ASTM A240 Type 304 support plate welded to the beam. A corrosion allowance of 1/16 inch is used in the design calculations. Welding procedures are in accordance with ASME Code Section IX or AWS D1.1 [A.8-11].

At coastal sites with operational experience of corrosion due to atmospheric chlorides, the front and rear DSC supports steel and weld filler metal have a minimum of 0.20%

copper content or are stainless steel. For carbon steels, weld material with 1% or more nickel is acceptable in lieu of 0.20% copper content. The copper content is equivalent to weathering steel [A.8-12], and nickel-bearing weld materials show equivalent corrosion resistance [A.8-13].

A.8.2.2 Material Properties The material properties used in the HSM-MX design analyses are listed in Table 8-4 through Table 8-6, Table 8-13, Table 8-23, and Table 8-24. Additionally, new materials used in the HSM-MX are provided in Table A.8-2 through Table A.8-4.

Each table cites the source for the properties. Table A.8-1 ties these materials to the individual components.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.8.2.2.1 EOS-37PTH and EOS-89BTH DSC No change from Section 8.2.2.1.

A.8.2.2.2 EOS TC Transfer Cask No change from Section 8.2.2.2.

A.8.2.2.3 HSM-MX Horizontal Storage Module In accordance with ACI 349-06, Section E.4.3, the strength properties of the concrete and reinforcing steel used in the HSM-MX structural analysis are taken at the maximum calculated temperature. Temperature-dependent mechanical properties of concrete and reinforcing steel are taken from [A.8-3] and presented in Table 8-23, and Table 8-24.

The material properties of the ASTM A992 Gr 50 steel used for the rear DSC support are listed in Table A.8-3, and the material properties for the ASTM A572 Gr. 50 front and rear stop plate and optional built-up I-beam are listed in Table A.8-2. The material properties used for the Type 304 stainless steel used for the front DSC supports and heat shields are provided in Table 8-5. The material properties used for the Type 316 stainless steel used as an option for the front DSC supports and heat shields are listed in Table 8-5.

The properties ASTM A588 for the axial retainer is provided in Table A.8-4.

A.8.2.2.4 NUHOMS EOS System Materials Employed in the Shielding Analysis Shielding properties of steel and concrete are obtained from [A.8-6] and are summarized in Table 8-30. Concrete used in the HSM-MX is modeled without steel rebar at a density of 138 pcf (2.211 g/cm3).

A.8.2.2.5 NUHOMS EOS System Materials Employed in the Criticality Analysis No change to Section 8.2.2.5.

A.8.2.3 Materials for ISFSI Sites with Experience of Atmospheric Chloride Corrosion Front and rear DSC supports at sites with operational experience of corrosion caused by atmospheric chlorides are fabricated from steels equivalent to weathering steel or stainless steel.

A.8.2.4 Weld Design and Inspection There are no changes to the weld design and inspection for the DSC and TC described in Section 8.2.4.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The rear DSC supports are bolted inside the HSM. The welds of the rear DSC supports are designed in accordance with the Manual of Steel Construction [8-7], and visually inspected in accordance with AWS D1.1 with acceptance criteria for statically loaded, non-tubular structures.

A.8.2.5 Galvanic and Corrosive Reactions A.8.2.5.1 Behavior of Aluminum and Neutron Absorbers in Water and Boric Acid No change to Section 8.2.5.1.

A.8.2.5.2 Behavior of Stainless Steel in Deionized Water and Weak Boric Acid No change to Section 8.2.5.2.

A.8.2.5.3 Behavior of Low-Alloy Steel in Deionized Water and Weak Boric Acid No change to Section 8.2.5.3.

A.8.2.5.4 Lubricants and Cleaning Agents No change to Section 8.2.5.4.

A.8.2.5.5 Corrosion of Canister Shell During Storage No change to Section 8.2.5.4.

A.8.2.5.6 Corrosion of DSC Front and Rear Supports The DSC front and rear supports are protected from direct exposure to precipitation, and are exposed only to the humidity and aerosols in the cooling air that flows through the HSM-MX. Exposed surfaces are coated with an inorganic zinc-rich rimer and high build epoxy enamel finish or galvanized, except for the stainless steel contact plates. The front DSC support is a stainless steel contact plate that sits atop a galvanized steel plate. Epoxy enamels such as Carboguard 890 are suitable for continuous service to 300 °F, while inorganic zinc primers such as Carbozinc 11 have much higher temperature resistance. The maximum temperature on the rear DSC supports is about 270 °F. The top coat is expected to experience chalking and other effects of radiation over 106 rad, but the inorganic primer coat is insensitive to radiation. Inspections for license extension [A.8-15, A.8-16] have found only minor local rusting. Nonetheless, the stress analysis removes 1/16 inch from all surfaces to account for corrosion. At independent spent fuel storage installations (ISFSIs) with operational experience of corrosion with atmospheric chlorides, additional protection is provided by specifying a minimum 0.2% copper content, which results in an adherent self-protecting oxide layer equivalent to weathering steel [A.8-12].

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.8.2.5.7 Corrosion of Transfer Cask No change to Section 8.2.5.7.

A.8.2.6 Creep Behavior of Aluminum No change to Section 8.2.6.

A.8.2.7 Bolt Applications No change to Section 8.2.7.

A.8.2.8 Protective Coatings and Surface Treatments No change to Section 8.2.8.

A.8.2.9 Neutron Shielding Materials No change to Section 8.2.9.

A.8.2.10 Materials for Criticality Control No change to Section 8.2.10.

A.8.2.11 Concrete and Reinforcing Steel No change to Section 8.2.11.

A.8.2.12 Seals No change to Section 8.2.12.

A.8.2.13 Low Temperature Ductility of Ferritic Steels No change to Section 8.2.13.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.8.3 Fuel Cladding No change to Section 8.3.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.8.4 Prevention of Oxidation Damage During Loading of Fuel No change to Section 8.4.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.8.5 Flammable Gas Generation No change to Section 8.5.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.8.6 DSC Closure Weld Testing No change to Section 8.6.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.8.7 References A.8-1 NUREG-1536, Standard Review Plan for Spent Fuel Dry Storage Systems at a General license Facility, Revision 1, U.S. Nuclear Regulatory Commission, July 2010.

A.8-2 American Society of Mechanical Engineers, ASME Boiler and Pressure Vessel Code, 2010 Edition with 2011 Addenda.

A.8-3 Mark Fintel, Handbook of Concrete Engineering, September 1974.

A.8-4 ACI-318-08, Building Code Requirement for Structural Concrete and Commentary, American Concrete Institute.

A.8-5 American Concrete Institute, Code Requirements for Nuclear Safety Related Concrete Structures, ACI-349-06.

A.8-6 PNNL-15870, Re. 1, Compendium of Material Composition Data for Radiation Transport Modeling, Pacific Northwest National Laboratory, March 2011.

A.8-7 American Institute of Steel Construction, Manual of Steel Construction, 13th Edition or 14th Edition.

A.8-8 Mark Fintel, Handbook of Concrete Engineering, Second Edition, September 1985.

A.8-9 ASTM A572/A572M, Standard Specification for High-Strength Low-Alloy Columbium-Vanadium Structural Steel, Latest Edition.

A.8-10 ACI-349-13, Code Requirements for Nuclear Safety Related Concrete Structures and Commentary, American Concrete Institute.

A.8-11 American Welding Society, AWS D1.1, March 2010, Structural Welding Code-Steel.

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A.8-13 C. P. Larrabee, S. K. Coburn, The Atmospheric Corrosion of Steels as Influenced by Changes in Chemical Composition, First International Congress on Metallic Corrosion, 1962 A.8-14 ASTM A992, Standard Specification for Structural Steel Shapes.

A.8-15 Duke Energy Carolinas, LLC, Oconee Nuclear Station, Docket No. 72-4, License No.

SNM-2503, License Renewal Application for the Site-Specific Independent Spent Fuel Storage Installation (ISFSI) - Response to Requests for Additional Information, License Amendment Request No. 2007-06, ADAMS ML090370066, January 30, 2009 (Response to Question A-4).

A.8-16 Calvert Cliffs Nuclear Power Plant, Independent Spent Fuel Storage Installation, Material License No. SNM-2505, Docket No. 72-8, Response to Request for Supplemental Information, RE: Calvert Cliffs Independent Spent Fuel Storage Installation License Renewal Application (TAC No. L24475), ADAMS ML12212A216, July 27, 2012.

A.8-17 CoC 1042 Appendix A, NUHOMS EOS System Generic Technical Specifications, Amendment 1.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.8-18 ASTM A588/A588M, "Standard Specification for High-Strength Low-Alloy Structural Steel, up to 50 ksi [345 MPa] Minimum Yield Point, with Atmospheric Corrosion Resistance."

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.8-1 HSM-MX Materials HSM Subcomponents Material HSM-MX walls, roof, floor, end shield walls Reinforced concrete with ASTM A615 or A706 Gr 60 reinforcing steel DSC Support Pedestal ASTM A992 Gr. 50 or ASTM A572 DSC Support Pedestal Stop Plate Gr. 50 ASTM A572 Gr. 50 DSC Support Pedestal Support Plate ASTM A240 Type 304 or 316 HSM-MX Door Reinforced concrete Door Steel Liner Assembly Steel Threaded Inserts Steel Inspection Penetration Sleeve Door Steel Axial Retainer Rod ASTM A588 Axial Retainer miscellaneous plate (fastener plate, spacer plate) Steel HSM-MX Heat Shields Stainless steel ASTM A240 Type 304 or 316 HSM-MX Outlet Vent Cover Reinforced concrete HSM-MX Outlet Vent Liners Carbon Steel HSM Inlet Vent Screen Assembly Carbon Steel Bird Screens and Dose Reduction Hardware Stainless steel or Carbon Steel Fasteners:

Bolts ASTM A193 Gr B7/

A325/A563/A490/A108 Washers ASTM A36/F436/F844/ Stainless Steel Nuts ASTM A194/A563/A194/ Carbon Steel Threaded Embedments:

Stud Bolt ASTM A193-Gr. B7, ASTM A193-B8 CL 2 or ASTM A193-B8M CL 2 Sleeve Nut ASTM A194 Gr 2H or A563 Gr A Nut ASTM A194 Gr 8M or A563 Gr A Page A.8-14 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.8-2 Material Properties, ASTM A572 Grade 50 Steel Temp E (2) Sy(3) Su(4) AVG (5)

(lb/in3) (6)

(°F) (103 ksi) (ksi) (ksi) (10-6 °F-1)

-20 70 29.0(7) 50.0(1) 65.0(1) 100 29.0 48.5 65.0 6.3 150 200 28.4 46.0 63.7 6.5 250 300 27.8 44.0 65.0 6.7 350 0.280 400 27.3 42.5 65.0 6.9 450 500 26.7 41.5 65.0 7.1 550 600 26.1 41.0 62.4 7.2 650 700 25.5 40.0 53.3 7.4 Notes

1. Reference [A.8-9].

2. Based on lowest rate of reduction provided in [A.8-8] Figure 7.5.

3. Based on lowest rate of reduction provided in [A.8-8] Figure 7.3.

4. Based on lowest rate of reduction provided in [A.8-8] Figure 7.4.

5. Based on lowest rate of reduction provided in [A.8-8] Figure 7.6.

6. ASME Section II Part D [A.8-2].

7. Based on AISC, Table B4.1 [A.8-7].

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.8-3 Material Properties, ASTM A992 Grade 50 Temp E (2) Yield Strength(3) Tensile Strength(4)

(5) (lb/in3)

(°F) (103 ksi) (ksi) (ksi)

-20 70 29.0(6) 50.0 (1) 65.0 (1) 100 29.0 48.5 65.0 150 200 28.4 46.0 63.7 250 0.280 300 27.8 44.0 65.0 350 400 27.3 42.5 65.0 450 500 26.7 41.5 65.0 Notes

1. Reference [A.8-14].

2. Based on lowest rate of reduction provided in [A.8-8] Figure 7.5.

3. Based on lowest rate of reduction provided in [A.8-8] Figure 7.3.

4. Based on lowest rate of reduction provided in [A.8-8] Figure 7.4.

5. ASME Section II Part D, Table PRD [A.8-2].

6. Based on AISC, Table B4.1 [A.8-7]

Page A.8-16 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.8-4 Material Properties, ASTM A588 Temp E (2) Yield Strength(3) Tensile Strength(4) Density(5)

(°F) (103 ksi) (ksi) (ksi) (lb/in3)

-20 70 29.0 (6) 50.0 (1) 70.0 (1) 100 29.0 48.5 70.0 150 200 28.4 46.0 68.6 250 0.280 300 27.8 44.0 70.0 350 400 27.3 42.5 70.0 450 500 26.7 41.5 70.0 Notes

1. Reference [A.8-18].

2. Based on lowest rate of reduction provided in [A.8-8] Figure 7.5.

3. Based on lowest rate of reduction provided in [A.8-8] Figure 7.3.

4. Based on lowest rate of reduction provided in [A.8-8] Figure 7.4.

5. ASME Section II Part D, Table PRD [A.8-2].

6. Based on AISC, Table B4.1 [A.8-7]

Page A.8-17 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.9 OPERATING PROCEDURES Table of Contents A.9 OPERATING PROCEDURES .................................................................................... A.9-1 A.9.1 Procedures for Loading the DSC and Transfer to the HSM-MX ................................................................................................................... A.9-2 A.9.1.1 TC and DSC Preparation .................................................................. A.9-2 A.9.1.2 DSC Fuel Loading ............................................................................ A.9-2 A.9.1.3 DSC Drying and Backfilling ............................................................. A.9-2 A.9.1.4 DSC Sealing Operations ................................................................... A.9-2 A.9.1.5 TC Downending and Transfer to ISFSI ............................................ A.9-2 A.9.1.6 DSC Transfer to the HSM-MX ......................................................... A.9-2 A.9.1.7 Monitoring Operations ...................................................................... A.9-4 A.9.2 Procedures for Unloading the DSC .............................................................. A.9-5 A.9.2.1 DSC Retrieval from the HSM-MX ................................................... A.9-5 A.9.2.2 Removal of Fuel from the DSC ........................................................ A.9-7 A.9.3 References ....................................................................................................... A.9-8 Page A.9-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Figures Figure A.9-1 HSM-MX System Loading Operations ........................................................... A.9-9 Page A.9-ii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.9 OPERATING PROCEDURES This chapter presents the operating procedures for the NUHOMS MATRIX (HSM-MX) described in previous chapters and shown on the drawings in Chapter A.1, Section A.1.3. The procedures include preparation of the NUHOMS EOS system dry shielded canister (DSC) and fuel loading, closure of the DSC, transfer to the independent spent fuel storage installation (ISFSI) using the transfer cask (TC), DSC transfer into HSM-MX, monitoring operations, and DSC retrieval from the HSM-MX.

The NUHOMS EOS transfer equipment, MATRIX loading crane (MX-LC),

MATRIX retractable roller tray (MX-RRT), and the existing plant systems and equipment are used to accomplish these operations.

The generic NUHOMS HSM-MX procedures described in this chapter have been developed to minimize the amount of time required to complete the subject operations, to minimize personnel exposure, and to assure that all operations required for DSC loading, closure, transfer, and storage are performed safely. Plant-specific ISFSI procedures are to be developed by each licensee in accordance with the requirements of 10 CFR 72.212(b) and the guidance of Regulatory Guide 3.61 [A.9-4]. These generic procedures are provided as a guide for the preparation of plant-specific procedures and serve to explain how the HSM-MX system operations are to be accomplished. They are not intended to be limiting in that the licensee may judge that alternate acceptable means are available to accomplish the same operational objective.

Pictograms of the HSM-MX System operations are presented in Figure A.9-1. The location of the various operations may vary with individual plant requirements.

Chapter A.9 provides a description as to how these operations are to be performed for the HSM-MX system.

See Chapter 1 for description of components.

The generic terms used throughout this section are as follows.

TC, or transfer cask is used for the TC125 transfer cask.

DSC is used for the EOS-37PTH DSC or EOS-89BTH DSC.

HSM-MX is used for the storage module.

MX-RRT is used to insert/retrieve DSC into/from HSM-MX module.

MX-LC is used to lift and position DSC with HSM-MX.

Note: If applicable to the planned DSC heat zone loading configuration per Figure 1a - 2 of the Technical Specifications [A.9-5], the forced cooling (FC) system should be verified operational prior to initiating the transfer operations and installed as soon as practical once the cask is on the transfer skid.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.9.1 Procedures for Loading the DSC and Transfer to the HSM-MX The following steps describe the recommended operating procedures for HSM-MX system. A pictorial representation of key phases of this process is provided in Figure A.9-1.

A.9.1.1 TC and DSC Preparation No change. See Section 9.1.1.

A.9.1.2 DSC Fuel Loading No change. See Section 9.1.2.

A.9.1.3 DSC Drying and Backfilling No change. See Section 9.1.3.

A.9.1.4 DSC Sealing Operations No change. See Section 9.1.4.

A.9.1.5 TC Downending and Transfer to ISFSI No change. See Section 9.1.5.

A.9.1.6 DSC Transfer to the HSM-MX CAUTION: The insides of empty compartments have the potential for high dose rates due to adjacent loaded compartments. Proper as low as reasonably achievable (ALARA) practices should be followed for operations inside these compartments and in the areas outside these compartments whenever the door from the empty compartment has been removed.

1. MX-LC Rails are installed, aligned and verified on the pad for the loading campaign.

Alignment is verified to the specifically designated features on the face of HSM-MX.

2. Prior to transporting the TC to the ISFSI, remove the HSM-MX door, inspect the compartment of the HSM-MX, removing any debris and ready the HSM-MX to receive a DSC. The doors on adjacent compartments should remain in place.

3. Inspect the DSC, and MX-RRT support pads inside HSM-MX compartment.

4. For ALARA purposes, reinstall the HSM-MX door.

5. Inspect the HSM-MX air inlet and outlets to ensure that they are clear of debris. Inspect the screens on the air inlet and outlets for damage.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 CAUTION: The insides of empty compartments have the potential for high dose rates due to adjacent loaded compartments. Proper ALARA practices should be followed for operations inside these compartments and in the areas outside these compartments whenever the MX-RRT operations are being performed.

6. Remove the MX-RRT cover plates and shield plugs.

7. Insert and install MX-RRT into HSM-MX. Extend the MX-RRT rollers, secure and verify that the rollers are extended.

8. Transport the TC from the plant's fuel/reactor building to the ISFSI along the designated transfer route.

9. Once at the ISFSI, move the transfer trailer inside the MX-LC at home position between the skid and the MX-LC grappling mechanism.

10. Use the MX-LC grappling mechanism to capture the skid along with TC, disengage the skid positioning system, move the skid up in the vertical direction to clear it from the transfer trailer, and then the transfer trailer is moved from MX-LC.

11. Remove the FC system, and install the ram cylinder assembly.

12. Remove the HSM-MX door.

13. Unbolt and remove the TC top cover plate.

14. Move MX-LC along the rail in front of HSM-MX until the TC is completely against the face of HSM-MX.

15. The skid is moved until the target compartment is reached. If necessary, adjust the MX-LC position until the MX-LC is properly aligned with the targeted compartment.

16. Secure the MX-LC/skid/cask to the front wall embedments of the HSM-MX using the restraints.

17. The hydraulic power unit is connected to the ram cylinder. The grapple is moved until it engages with grapple ring of the canister. Using the ram cylinder, fully insert the DSC into the HSM-MX compartment.

18. Disengage the ram grapple mechanism so that the grapple is retracted away from the DSC grapple ring.

19. Retract the MX-RRT rollers; the DSC is lowered onto the HSM-MX front and rear DSC supports.

Page A.9-3 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Note: The time limit for transfer operations, if any, starts with the initiation of the TC/DSC annulus water draining described in Step 9 of Section 9.1.4 and ends when the DSC is fully seated onto the front and rear DSC supports.

CAUTION: Verify that the applicable time limits for transfer operations of Section 3.1.3 of the Technical Specifications [A.9-5] are met.

20. Remove the wall embedments from the HSM-MX.

21. Retract the skid with TC from docking position and lower it.

22. Place the HSM-MX door. Verify that the HSM dose rates are compliant with the limits specified in Section 5.1.2 of the Technical Specifications [A.9-5].

23. Move MX-LC to its home position, and the transfer trailer is moved into accepting position.

24. Lower the Skid along with TC onto the transfer trailer. Reconnect the skid positioning system. Remove the ram cylinder assembly.

25. Bolt the TC cover plate into place, tightening the bolts to the required torque in a star pattern.

CAUTION: The insides of empty compartments have the potential for high dose rates due to adjacent loaded compartments. Proper ALARA practices should be followed for operations inside these compartments and in the areas outside these compartments whenever the MX-RRT operations are being performed.

26. Remove the MX-RRT from the HSM-MX.

27. Place MX-RRT shield plugs and cover plates for the MX-RRT accesses.

28. Move the transfer trailer from MX-LC to the designated equipment storage area. Return the remaining transfer equipment to the storage area.

29. Close and lock the ISFSI access gate and activate the ISFSI security measures.

A.9.1.7 Monitoring Operations

1. Perform routine security surveillance in accordance with the licensee's ISFSI security plan.

2. Perform a daily visual surveillance of the HSM-MX air inlets and outlets (bird screens) to verify that no debris is obstructing the HSM-MX vents in accordance with Section 5.1.3.2(a) of the Technical Specification [A.9-5] requirements, or, perform a temperature measurement for each EOS-HSM in accordance with Section 5.1.3.2(b) of the Technical Specification [A.9-5] requirements.

Page A.9-4 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.9.2 Procedures for Unloading the DSC The following section outlines the procedures for retrieving the DSC from the HSM-MX. The procedures for removing the FAs from the DSC are the same as described in Section 9.2.

A.9.2.1 DSC Retrieval from the HSM-MX

1. Ready the TC, transfer trailer, loading crane, and skid for service. Fill the TC liquid neutron shield and remove the top cover plate from the TC. Transport the trailer into the ISFSI.

Note: Verify that a TC spacer of appropriate height is placed inside the TC to provide the correct airflow and interface at the top of the TC during cutting and unloading operations for DSCs that are shorter than the TC cavity length.

2. MATRIX MX-LC rails are installed, aligned and verified on the pad for the unloading campaign. Alignment is verified to the specifically designated features on the face of HSM-MX.

3. Move the transfer trailer inside the MX-LC home position between the skid and the MX-LC grappling mechanism.

4. Use the MX-LC grappling mechanism to capture the skid along with TC, disengage the skid positioning system, move the skid up vertically to clear it from the transfer trailer, then move the transfer trailer from the MX-LC.

5. Install the ram cylinder assembly.

CAUTION: The insides of empty compartments have the potential for high dose rates due to adjacent loaded compartments. Proper ALARA practices should be followed for operations inside these compartments and in the areas outside these compartments whenever the MX-RRT operations are being performed.

6. Remove the MX-RRT shield blocks plugs and cover plates.

7. Insert and install MX-RRT into HSM-MX. Extend the MX-RRT rollers, secure and verify that the rollers are extended.

CAUTION: The insides of empty compartments have the potential for high dose rates due to adjacent loaded compartments. Proper ALARA practices should be followed for operations inside these compartments and in the areas outside these compartments whenever the door from the empty compartment has been removed.

8. Remove the HSM-MX door.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20

9. Unbolt and remove the TC top cover plate.

10. Move MX-LC along the rail in front of HSM-MX until the TC is completely against the face of HSM-MX.

11. Move MX-LC along the face of the HSM-MX to the target HSM-MX compartment.

12. The skid is moved in to the target compartment. If necessary, adjust the MX-LC position until the MX-LC is properly aligned with the targeted cavity.

13. Secure the MX-LC/skid/cask to the front wall embedments of the HSM-MX using the restraints.

14. The hydraulic power unit is connected to the ram cylinder. The grapple is moved until it engages with the grapple ring of the canister. Using ram cylinder, fully insert the ram into HSM-MX compartment.

15. Operate the ram grapple and engage the grapple arms with the DSC grapple ring.

16. Recheck all alignment marks and ready all systems for DSC transfer.

CAUTION: The time limits for the unloading of the DSC should be determined using the heat loads at the time of the unloading operation and the methodology presented in Sections 4.5 and 4.6 before pulling the DSC out of the HSM-MX.

17. Activate the ram to pull the DSC into the TC.

18. Disengage the ram grapple mechanism so that the grapple is retracted away from the DSC grapple ring.

19. Retract and disengage the ram system from the TC and move it clear of the TC. Remove the TC embedments from the HSM-MX.

20. Retract the skid with TC from docking position and lower it.

21. Move MX-LC to its home position, and move the transfer trailer to accepting position.

22. Lower the skid along with TC onto the transfer trailer. Reconnect the skid positioning system, remove the ram cylinder assembly, and reinstall the FC system.

23. Bolt the TC cover plate into place, tightening the bolts to the required torque in a star pattern.

CAUTION: The insides of empty compartments have the potential for high dose rates due to adjacent loaded compartments. Proper ALARA practices should be followed for operations inside these compartments and in the areas outside these compartments whenever the MX-RRT operations are being performed.

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24. Disconnect MX-RRT operating mechanism and retract MX-RRT to MX-RRT handling device.

25. Place MX-RRT shield plugs and cover plates for the MX-RRT accesses.

26. Move the transfer trailer from MX-LC and ready the trailer for transfer.

27. Replace the HSM-MX door.

A.9.2.2 Removal of Fuel from the DSC No change, see Section 9.2.2.

Page A.9-7 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.9.3 References A.9-1 U.S. Nuclear Regulatory Commission, Office of the Nuclear Material Safety and Safeguards, Safety Evaluation of VECTRA Technologies Response to Nuclear Regulatory Commission Bulletin 96-04 For the NUHOMS-24P and NUHOMS-7P.

A.9-2 U.S. Nuclear Regulatory Commission Bulletin 96-04, Chemical, Galvanic or Other Reactions in Spent Fuel Storage and Transportation Casks, July 5, 1996.

A.9-3 SNT-TC-1A, American Society for Nondestructive Testing, Personnel Qualification and Certification in Nondestructive Testing, 2006.

A.9-4 U.S. Nuclear Regulatory Commission, Regulatory Guide 3.61 Standard Format and Content for a Topical Safety Analysis Report for a Spent Fuel Dry Storage Container, February 1989.

A.9-5 CoC 1042 Appendix A, NUHOMS EOS System Generic Technical Specifications, Amendment 1.

Page A.9-8 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.9-1 NUHOMS MATRIX Loading Operations 4 Pages Page A.9-9 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20

5) Tow Trailer to Loading Crane at ISFSI

6) Transfer TC from Trailer to Loading Crane

7) Insert and Install Retrievable Roller Tray (MX-RRT)

Figure A.9-1 NUHOMS MATRIX Loading Operations 4 Pages Page A.9-10 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20

8) Remove the Transfer Cask Cover.

9) Align Transfer Cask at X-Plane Direction, Engage Ram Grapple with Canister, HSM Door Is Removed.

10) Align Transfer Cask at Z-Direction.

Figure A.9-1 NUHOMS MATRIX Loading Operations 4 Pages Page A.9-11 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20

11) Transfer Canister to HSM-MX

12) Remove Cask and Install HSM-MX Door

13) Transfer Cask from Loading Crane to Trailer Figure A.9-1 NUHOMS MATRIX Loading Operations 4 Pages Page A.9-12 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.10 ACCEPTANCE TESTS AND MAINTENANCE PROGRAM Table of Contents A.10 ACCEPTANCE TESTS AND MAINTENANCE PROGRAM .............................. A.10-1 A.10.1 Acceptance Tests .......................................................................................... A.10-2 A.10.1.2 Leak Tests ....................................................................................... A.10-2 A.10.1.3 Visual Inspection and Non-Destructive Examinations ................... A.10-2 A.10.1.4 Shielding Tests ................................................................................ A.10-2 A.10.1.5 Neutron Absorber Tests .................................................................. A.10-2 A.10.1.6 Thermal Acceptance Tests .............................................................. A.10-3 A.10.1.7 Low Alloy High Strength Steel for Basket Structure ..................... A.10-3 A.10.1.8 Cask Identification .......................................................................... A.10-3 A.10.2 Maintenance Program ................................................................................. A.10-4 A.10.3 Repair, Replacement, and Maintenance .................................................... A.10-5 A.10.4 References ..................................................................................................... A.10-6 Page A.10-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.10 ACCEPTANCE TESTS AND MAINTENANCE PROGRAM This chapter specifies the acceptance testing and maintenance program for important-to-safety (ITS) components of the NUHOMS MATRIX (HSM-MX).

Page A.10-1 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.10.1 Acceptance Tests The addition of the HSM-MX to the standardized NUHOMS EOS system does not result in any change to the pre-operational tests described in Section 10.1, since the EOS-DSCs and EOS-TCs involved are not changed.

A.10.1.1.1 DSC No change to Section 10.1.1.1.

A.10.1.1.2 HSM-MX Concrete mix design, placement, and testing are performed in accordance with ACI-318 [A.10-1]. The minimum 28-day compressive strength is 5000 psi if controls are placed on the aggregate type or coefficient of thermal expansion as described in Section 8.2.1.3. If the alternative described in that section is used, the minimum is 7000 psi. In accordance with American Concrete Institute (ACI) 349 Appendix E, paragraph E.4.3 [A.10-2], compressive testing of the concrete mix design for the monolith, and doors is conducted after heating the test cylinders prior to testing. For the HSM-MX, the testing of the specimens are performed at a temperature of 500 °F per Table 4-17. See Sections 4.4.4 and 5.3 of the Technical Specifications [A.10-4].

The reinforcing steel, ITS fasteners, and steel for the door and the front and rear DSC supports are tested for mechanical properties in accordance with the governing specifications called out on the drawings in Chapter A.1.

Weld procedures and welders for the front and rear DSC supports are qualified in accordance with ASME Code Section IX or American Welding Society (AWS) D1.1

[A.10-3].

A.10.1.1.3 Transfer Cask No change to Section 10.1.1.3.

A.10.1.2 Leak Tests No change to Section 10.1.2.

A.10.1.3 Visual Inspection and Non-Destructive Examinations No change to Section 10.1.3.

A.10.1.4 Shielding Tests No change to Section 10.1.4.

A.10.1.5 Neutron Absorber Tests No change to Section 10.1.5.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.10.1.6 Thermal Acceptance Tests No change to Section 10.1.6.

A.10.1.7 Low Alloy High Strength Steel for Basket Structure No change to Section 10.1.7.

A.10.1.8 Cask Identification No change to Section 10.1.8.

Page A.10-3 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.10.2 Maintenance Program No change to Section 10.2 associated with the addition of the HSM-MX. HSM inspections from Section 10.2.1.2 are applicable to the HSM-MX.

Page A.10-4 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.10.3 Repair, Replacement, and Maintenance No change to Section 10.3 associated with the addition of the HSM-MX.

Requirements of Section 10.3.2 for the HSM are applicable to the HSM-MX.

Page A.10-5 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.10.4 References A.10-1 ACI 318-08, Building Code Requirements for Structural Concrete and Commentary, American Concrete Institute, Detroit, MI.

A.10-2 ACI 349-06, Code Requirements for Nuclear Safety Related Structures, American Concrete Institute, Detroit, MI.

A.10-3 American Welding Society, AWS D1.1/D1.1M, Structural Welding Code - Steel.

A.10-4 CoC 1042 Appendix A, NUHOMS EOS System Generic Technical Specifications, Amendment 1.

Page A.10-6 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.11 RADIATION PROTECTION Table of Contents A.11 RADIATION PROTECTION ................................................................................... A.11-1 A.11.1 Radiation Protection Design Features ....................................................... A.11-2 A.11.2 Occupational Dose Assessment ................................................................... A.11-3 A.11.2.1 EOS-DSC Loading, Transfer, and Storage Operations .................. A.11-3 A.11.2.2 EOS-DSC Retrieval Operations ...................................................... A.11-3 A.11.2.3 Fuel Unloading Operations ............................................................. A.11-4 A.11.2.4 Maintenance Operations ................................................................. A.11-4 A.11.2.5 Doses during ISFSI Expansion ....................................................... A.11-4 A.11.3 Offsite Dose Calculations ............................................................................ A.11-5 A.11.3.1 Normal Conditions (10 CFR 72.104) ............................................. A.11-5 A.11.3.2 Accident Conditions (10 CFR 72.106) ........................................... A.11-8 A.11.4 Ensuring that Occupational Radiation Exposures Are ALARA ............. A.11-9 A.11.4.1 Policy Considerations ..................................................................... A.11-9 A.11.4.2 Design Considerations .................................................................... A.11-9 A.11.4.3 Operational Considerations ............................................................. A.11-9 A.11.5 References ................................................................................................... A.11-10 Page A.11-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Tables Table A.11-1 Occupational Dose Rates .......................................................................... A.11-11 Table A.11-2 Occupational Exposure, EOS-TC108 with EOS-89BTH DSC ................ A.11-12 Table A.11-3 Occupational Exposure, EOS-TC125/135 with EOS-37PTH DSC.......... A.11-14 Table A.11-4 Occupational Exposure, EOS-TC125 with EOS-89BTH DSC ................ A.11-16 Table A.11-5 Total Annual Exposure from ISFSI .......................................................... A.11-18 Table A.11-6 ISFSI Surface Sources .............................................................................. A.11-19 Table A.11-7 2x11 Back-to-Back Dose Rates ................................................................ A.11-20 Table A.11-8 Two 1x11 Front-to-Front Dose Rates ....................................................... A.11-22 Table A.11-9 2x11 Back-to-Back Accident Dose Rates ................................................. A.11-24 Page A.11-ii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 List of Figures Figure A.11-1 Total Annual Exposure from the ISFSI .................................................... A.11-26 Figure A.11-2 2x11 ISFSI MCNP Geometry ................................................................... A.11-27 Figure A.11-3 Two 1x11 ISFSI MCNP Geometry........................................................... A.11-28 Page A.11-iii Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.11 RADIATION PROTECTION This chapter describes the design features of the NUHOMS MATRIX (HSM-MX) that maintain radiation exposure to site personnel as low as reasonably achievable (ALARA), as well as minimize exposure to the public. An occupational dose assessment for operation of the HSM-MX is provided. Radiation exposures to offsite individuals are also computed for both normal and accident conditions of an independent spent fuel storage installation (ISFSI). This chapter provides an example of how to demonstrate compliance with the relevant radiological requirements of 10 CFR Part 20 [A.11-1], 10 CFR Part 72 [A.11-2], and 40 CFR Part 190 [A.11-3]. Each user must perform site-specific calculations to account for the actual layout of the HSM-MXs and fuel source.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.11.1 Radiation Protection Design Features The HSM-MX has design features that ensure a high degree of integrity for the confinement of radioactive materials and reduction of direct radiation exposures during storage. These features are described in Section A.11.4.2.

Page A.11-2 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.11.2 Occupational Dose Assessment This section provides estimates of occupational dose for typical EOS transfer cask (EOS-TC) and ISFSI loading operations. Assumed annual occupancy times, including the anticipated maximum total hours per year for any individual, and total person-hours per year for all personnel for each radiation area during normal operation and anticipated operational occurrences, will be evaluated by the licensee in a 10 CFR 72.212 evaluation to address the site-specific ISFSI layout, inspection, and maintenance requirements. In addition, the estimated annual collective doses associated with loading operations will be addressed by the licensee in a 10 CFR 72.212 evaluation.

A.11.2.1 EOS-DSC Loading, Transfer, and Storage Operations The dose rates used in the occupational dose assessment are summarized in Table A.11-1. The EOS-TC loading and transfer dose rates are unchanged from the values presented in Chapter 11. The HSM-MX dose rate reported in Table A.11-1 is the average dose rate on the front surface of an HSM-MX and is obtained from Chapter A.6.

The estimated occupational exposures to ISFSI personnel during loading, transfer, and storage operations using the EOS-TC108 (time and number of workers may vary depending on individual ISFSI practices) are provided in Table A.11-2 for the EOS-89BTH DSC. Similar operations for the EOS-TC125/135 are provided in Table A.11-3 and Table A.11-4. Transfer of the EOS-37PTH DSC to the HSM-MX using the EOS-TC108 is not currently authorized. The task times, number of personnel required, and total doses are listed in these tables. The total exposure results are as follows:

EOS-TC108 with EOS-89BTH DSC: 4,535 person-mrem (~4.5 person-rem)

EOS-TC125/135 with EOS-37PTH DSC: 3,200 person-mrem (~3.2 person-rem)

EOS-TC125 with EOS-89BTH DSC: 2,523 person-mrem (~2.5 person-rem)

The exposures provided above are bounding estimates. Measured exposures from typical NUHOMS System loading campaigns have been 600 mrem or lower per canister for normal operations, and exposures for the HSM-MX are expected to be similar.

Regulatory Guide 8.34 [A.11-4] is to be used to define the onsite occupational dose and monitoring requirements.

A.11.2.2 EOS-DSC Retrieval Operations Occupational exposures to ISFSI personnel during EOS-DSC retrieval are similar to those exposures calculated for EOS-DSC insertion. Dose rates for retrieval operations will be lower than those for insertion operations due to radioactive decay of the spent fuel inside the HSM-MX. Therefore, the dose rates for EOS-DSC retrieval are bounded by the dose rates calculated for insertion.

Page A.11-3 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.11.2.3 Fuel Unloading Operations No change to Section 11.2.3.

A.11.2.4 Maintenance Operations The dose rates for surveillance activities are shown in Table A.11-7 and Table A.11-8 for doses rates 6.1 m from the front of an HSM-MX. The 6.1-meter dose rate is a conservative estimate for surveillance activities. The HSM-MX surface dose rates provided in Chapter A.6 can be used for temperature sensor maintenance activities, including calibration and repair.

The general licensee will evaluate the additional dose to personnel from ISFSI operations, based on the particular storage configuration and site personnel requirements.

A.11.2.5 Doses during ISFSI Expansion During the ISFSI expansion using the construction joint option, the removable end shield wall is absent, and the two complete compartments (one upper and one lower) at the end of the module are empty. The maximum dose rate at the end of the module for the array expansion configuration is 3.64 mrem/hr, which is low (see Section A.6.4.4). If the array terminates at an expansion joint, two empty compartments (one upper and one lower) are also required at the end of the array, and dose rates are bounded by the construction joint option. The maximum dose rate on the surface of the integral shield wall is 4.20 mrem/hr (see Table A.6-2). Therefore, the end dose rate during array expansion activities is approximately the same as the end dose rate with an integral end shield wall, and elevated dose rates during array expansion activities are not anticipated.

Page A.11-4 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.11.3 Offsite Dose Calculations Calculated dose rates in the immediate vicinity of the HSM-MX are presented in Chapter A.6, which provides a detailed description of source term configuration, analysis models, and bounding dose rates. The HSM-MX dose rates reported in Chapter A.6 are conservatively based on the EOS-89BTH DSC HLZC #1, which is not authorized for storage in the HSM-MX. Offsite dose rates and annual exposures are presented in this section. Neutron and gamma-ray offsite dose rates are computed, including skyshine, in the vicinity of the two generic ISFSI layouts containing design-basis contents.

A.11.3.1 Normal Conditions (10 CFR 72.104)

Offsite dose rates are a result of direct radiation from the ISFSI. The operation of loading an HSM-MX occurs over a very short time period and contributes negligibly to the offsite dose rates. Therefore, normal condition offsite dose rate calculations are computed only for a loaded ISFSI. No off-normal conditions have been identified that affect offsite dose rates.

Two generic ISFSI configurations are considered that each store 22 EOS-DSCs. In the first configuration, the 22 DSCs are stored in a single HSM-MX with the DSCs in a 2x11 back-to-back configuration. In the 2x11 back-to-back configuration, the front of the modules face outward and the rows are separated by a wall of concrete. In the second configuration, the 22 DSCs are stored in two HSM-MX systems that each contain 11 DSCs in a 1x11 configuration. In the two 1x11 front-to-front configuration, the modules are aligned with the rear shield walls facing outward and the front of the modules facing inward, separated by 32 ft. This configuration has the advantage of minimizing the dose rate near the ISFSI because the inlet vents are directed inward in an area that would not normally be occupied.

It is noted in Chapter A.6 that HSM-MX dose rates are larger for the EOS-89BTH DSC compared to the EOS-37PTH DSC. Therefore, offsite dose rates are computed only for the bounding EOS-DSC. This evaluation provides results for distances ranging from 6.1 to 600 m from each face for the two configurations.

The Monte Carlo computer code Monte Carlo N-Particle Version 5 (MCNP5)

[A.11-5] is used to calculate the dose rates at the specified locations around the HSM-MX. The results of this evaluation provide an example of how to demonstrate compliance with the relevant radiological requirements of 10 CFR 20, 10 CFR 72, and 40 CFR 190 for a specific site. Each user must perform site-specific calculations to account for the actual layout of the HSM-MXs and fuel source.

Page A.11-5 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 The total annual exposure for each ISFSI layout as a function of distance from each face is given in Table A.11-5 and plotted in Figure A.11-1. The total annual exposure estimates are based on 100% occupancy for 365 days. At large distances, the annual exposure from the 2x11 back-to-back configuration is similar to the two 1x11 front-to-front configuration. Per 10 CFR 72.104, the annual whole-body dose to an individual at the site boundary is limited to 25 mrem. Based on the data shown in Table A.11-5, the offsite dose rate drops below 25 mrem at a distance of approximately 349 m from the ISFSI. Therefore, 349 m is the minimum distance with design basis fuel to the site boundary for the HSM-MX system with 22-DSCs; however, a shorter distance can be demonstrated in a site-specific calculation.

The methodology, inputs, and assumptions for the MCNP analyses are summarized in the following paragraphs.

The 2x11 back-to-back configuration is modeled as a box enveloping the HSM-MX, including the 44 inch thick shield walls on the two ends. Source particles are started on the surfaces of the box. A sketch of this geometry is shown in Figure A.11-2. The interiors of the HSM-MX and shield walls are modeled as air.

Most particles that enter the interiors of the HSM-MX and shield walls will, therefore, pass through unhindered.

The HSM-MXs in the two 1x11 front-to-front configuration are modeled as two boxes that envelop each 1x11 row, including the 44-inch thick shield walls on the two ends and 44 inch thick rear shield wall in each row. Source particles are started on the surfaces of one of the modules, which is modeled as air. The opposite module is modeled as solid concrete. A sketch of this geometry is shown in Figure A.11-3. The dose field is then created for a source in both modules by accounting for model symmetry, as indicated in Figure A.11-3.

The ISFSI approach slab is modeled as concrete. Because the ground composition has, at best, only a secondary impact on the dose rates at the detectors, any differences between this assumed layout and the actual layout would not have a significant effect on the site dose rates.

The universe is a sphere surrounding the ISFSI. To account for skyshine, the radius of this sphere (r=500,000 cm) is more than 10 mean free paths for neutrons and 50 mean free paths for gammas in air, thus ensuring that the model is of a sufficient size to include all interactions, including skyshine, affecting the dose rate at the detectors.

The 2x11 and two 1x11 surface sources are input to reproduce the average dose rate and spectrum on the surface of the HSM-MX, as computed in Chapter A.6.

The surface average fluxes on the front, roof, side, and rear of the HSM-MXs are explicitly computed and are provided in Tables A.6-3 through A.6-5. The primary and secondary gamma fluxes are simply summed in the gamma input file.

These surface spectra are directly input to MCNP for each face.

Source particles on the ISFSI surface are specified with a cosine distribution. For a cosine distribution, the outward particle current is equal to half of the flux. The MCNP source description requires the number of source particles per second emitted on each face (particle current). Because the current is half of the flux for a cosine distribution, and the flux at each face is known, the input current for each Page A.11-6 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 face (particles/s) is computed as A*F/2, where A is the area of the face (cm2) and F is the total flux on each face (particles/cm2-s). The surface source evaluations are summarized in Table A.11-6.

ANSI/ANS 6.1.1-1977 flux-to-dose rate factors are utilized [A.11-6]. These factors are provided in Table 6-51.

For the 2x11 back-to-back configuration with end shield walls, the box dimensions are 1260 cm wide, 2096 cm long, and 903 cm high. For the two 1x11 front-to-front configuration with end and back shield walls, the box dimensions are 704 cm wide, 2096 cm long, and 903 cm high. The two 1x11 rows are 975 cm (32 ft) apart.

Dose rates are calculated for distances of 6.1 m (20 ft) to 600 m from the edges of the two ISFSI configurations. Point detectors are placed at the following locations, as measured from each face of the box: 6.095 m (20 ft), 10 m, 20 m, 30 m, 40 m, 50 m, 60 m, 70 m, 80 m, 90 m, 100 m, 200 m, 300 m, 400 m, 500 m, and 600 m. Each point detector is placed 91 cm (~3 ft) above the ground.

The MCNP results for the 2x11 back-to-back and two 1x11 front-to-front configurations are summarized in Table A.11-7 and Table A.11-8, respectively. At near distances, the 2x11 configuration results in larger front dose rates than the outward rear of the two 1x11 configuration. For example, the 6.1 m front dose rate is 16.5 mrem/hr for the 2x11 configuration compared to 1.15 mrem/hr for the two 1x11 configuration. However, at near distances, the two 1x11 configuration results in nominally larger side dose rates than the 2x11 configuration.

At large distances, the dose rates are approximately the same, regardless of configuration or direction from the ISFSI, as the dose rate at large distances is dominated by skyshine from the radiation streaming from the roof outlet vents. Also, note that the neutron dose rate is negligible compared to the gamma dose rate at all dose rate locations.

The total Monte Carlo uncertainty is < 5% for all dose rate locations. The annual exposures reported in Table A.11-5 are simply the computed dose rates multiplied by 8760 hours0.101 days <br />2.433 hours <br />0.0145 weeks <br />0.00333 months <br /> (1 year).

The preceding analyses and results are intended to provide high estimates of dose rates for generic ISFSI layouts. The written evaluations performed by a general licensee for the actual ISFSI must consider the type and number of storage units, layout, characteristics of the irradiated fuel to be stored, site characteristics (e.g., berms, distance to the controlled area boundary, etc.), and reactor operations at the site in order to demonstrate compliance with 10 CFR 72.104.

Page A.11-7 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.11.3.2 Accident Conditions (10 CFR 72.106)

Per 10 CFR 72.106, the exposure to an individual at the site boundary due to an accident is limited to 5 rem. In an accident, the HSM-MX outlet vent covers and all dose reduction hardware may be lost. In addition, it is assumed that the HSM-MX is in an expansion configuration with the removable end shield wall absent and that a missile strike has damaged two interior walls. This accident scenario results in elevated dose rates on the front, roof, and side of the ISFSI. The average HSM-MX roof, front, and side dose rates and fluxes in an accident are provided in Chapter A.6, Tables A.6-6 through A.6-8.

Table A.11-9 shows the bounding dose rate as a function of distance from a 2x11 back-to-back configuration of HSM-MXs for the accident configuration described above. These dose rates are calculated assuming damage to every module in the array.

This is a highly conservative scenario that is not credible, as an accident is not expected to damage every module.

MCNP inputs for a 2x11 ISFSI accident configuration are prepared using the same method as described for the normal condition models. At a distance of 200 m and 349 m from the ISFSI, the accident dose rate is approximately 0.436 mrem/hr and 0.061 mrem/hr, respectively. It is assumed that the recovery time for this accident is five days (120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br />). Therefore, the total exposure to an individual at a distance of 200 m and 349 m is approximately 52 mrem and 7.3 mrem, respectively. This is significantly less than the 10 CFR 72.106 limit of 5 rem.

The EOS-TC may also be damaged in an accident during transfer operations, which would result in an offsite dose, see the discussion in Section 11.3.2.

Page A.11-8 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.11.4 Ensuring that Occupational Radiation Exposures Are ALARA A.11.4.1 Policy Considerations No change to Section 11.4.1.

A.11.4.2 Design Considerations No change to the EOS-DSC and EOS-TC, see Section 11.4.2.

The HSM-MX storage modules include no active components that require periodic maintenance, thereby minimizing potential personnel dose due to maintenance activities.

The HSM-MXs provide thick concrete shielding, and the shielding design features of the storage modules minimize occupational exposure for any activities on or near the ISFSI.

Regulatory Position 2 of Regulatory Guide 8.8 is incorporated into the design considerations, see Section 11.4.2.

A.11.4.3 Operational Considerations The areas of highest operational dose of HSM-MX are the front of a loaded HSM-MX at the air inlet vent. Operating procedures, temporary shielding, and personnel training are put into practice to minimize personnel exposure in this area.

The HSM-MX is designed to be essentially maintenance free. It is a passive system with no moving parts. The only anticipated maintenance procedures are the visual inspection of the bird screens on the HSM-MX ventilation inlet and outlet openings, and periodic maintenance of the temperature sensors.

Page A.11-9 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.11.5 References A.11-1 Title 10, Code of Federal Regulations, Part 20, Standards for Protection Against Radiation.

A.11-2 Title 10, Code of Federal Regulations Part 72, Licensing Requirements for the Independent Storage of Spent Nuclear Fuel and High-Level Radioactive Waste, and Reactor-Related greater than Class C Waste.

A.11-3 Title 40, Code of Federal Regulations, Part 190, Environmental Radiation Protection Standards for Nuclear Power Operations.

A.11-4 U.S. Nuclear Regulatory Commission, Regulatory Guide 8.34, Monitoring Criteria and Methods to Calculate Occupational Radiation Doses, July 1992.

A.11-5 Oak Ridge National Laboratory, MCNP/MCNPX - Monte Carlo N-Particle Transport Code System Including MCNP5 1.40 and MCNPX 2.5.0 and Data Libraries, CCC-730, RSICC Computer Code Collection, January 2006.

A.11-6 ANSI/ANS-6.1.1-1977, Neutron and Gamma-Ray Fluence-to-Dose Factors, American Nuclear Society, LaGrange Park, Illinois, March 1977.

Page A.11-10 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-1 Occupational Dose Rates Dose Rate (mrem/hr)

EOS-TC108 EOS-TC125/135 Dose Rate Averaged EOS-89BTH EOS-37PTH EOS-89BTH Location Segments Config. DSC DSC DSC DRL1 through (1) (1) (1) (1) (1)

DRL10 Front face HSM-MX surface - 50 50 50 (HMX) average Note 1: Information pertaining to dose rate locations DRL1 through DRL10 is provided in Table 11-1.

Page A.11-11 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-2 Occupational Exposure, EOS-TC108 with EOS-89BTH DSC (2 Pages)

Dose  % of Dose Rate No. of Duration Dose Rate (person Total No. (2) Operation Configuration Location People (hr) (mrem/hr) -mrem) Dose 1 Place an empty EOS-DSC into an EOS-TC and prepare the EOS-TC for N/A N/A 6 4.00 0 0 0%

placement into the spent fuel pool.

2 Move the EOS-TC containing an EOS-DSC without fuel into the spent fuel N/A N/A 6 1.50 0 0 0%

pool.

3 Remove the loaded EOS-TC from the fuel pool and place in the Decon. DRL1 2 0.25 194 97 2.1%

decontamination area.

4 Install neutron shield. Fill neutron Decon. DRL4 3 0.33 1050 1040 22.9%

shield with water.

5 Prep and weld inner top cover plate. Welding DRL3 2 0.75 198 297 6.5%

6 Vacuum dry and backfill with helium. Welding DRL3 2 0.50 198 198 4.4%

7 Weld outer top cover plate and port covers, perform non-destructive Welding DRL3 2 0.50 198 198 4.4%

examination.

8 Drain annulus. Install EOS-TC aluminum top cover. Ready the Transfer DRL5 1 0.50 586 293 6.5%

support skid and transfer trailer.

9 Place the EOS-TC onto the skid and Transfer DRL2 2 0.33 747 498 11.0%

trailer. Secure the EOS-TC to the skid.

10 Install retractable roller tray (RRT). Transfer HMX 2 2.00 50 200 4.4%

11 Remove aluminum top cover and Transfer DRL3 2 0.33 199 133 2.9%

replace with steel top cover.

12 Transfer the EOS-TC to ISFSI. N/A N/A 6 1.83 0 0 0%

Page A.11-12 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-2 Occupational Exposure, EOS-TC108 with EOS-89BTH DSC (2 Pages)

Dose  % of Dose Rate No. of Duration Dose Rate (person Total No. (2) Operation Configuration Location People (hr) (mrem/hr) -mrem) Dose 13 Position the EOS-TC inside the loading Transfer HMX+DRL2 2 0.50 797 797 17.6%

crane (MX-LC).

14 Remove forced cooling system (if used) and install the ram cylinder Transfer DRL9 2 0.50 137 137 3.0%

assembly.

15 Remove HSM-MX door. Transfer HMX 2 0.50 50 50 1.1%

16 Remove the EOS-TC top cover. Transfer HMX+DRL6 2 0.67 150 200 4.4%

17 Align and dock the EOS-TC with the HSM-MX. Secure the EOS-TC to the Transfer HMX+DRL7 2 0.25 239 120 2.6%

HSM-MX.

18 Transfer the EOS-DSC from the EOS-TC to the HSM-MX using the ram N/A N/A 3 0.50 0 0 0%

cylinder.

19 Disengage the ram and un-dock the Transfer HMX+DRL10 2 0.08 171 29 0.6%

EOS-TC from the HSM-MX.

20 Install HSM-MX access door. Move EOS-TC to the transfer skid for Transfer HMX 2 0.50 50 50 1.1%

removal.

21 Uninstall RRT. Transfer HMX 2 2.00 50 200 4.4%

(1)

Total 4535 Note:

(1) A building crane hang-up off-normal event adds 776 person-mrem (DRL1/decon

• 4 workers

• 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />).

(2) Occupational exposures for steps 1 through 9 are consistent with Chapter 11, Table 11-3.

Page A.11-13 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-3 Occupational Exposure, EOS-TC125/135 with EOS-37PTH DSC (2 Pages)

Dose  % of Dose Rate No. of Duration Dose Rate (person Total No. (2) Operation Configuration Location People (hr) (mrem/hr) -mrem) Dose 1 Drain neutron shield if necessary. Place an empty EOS-DSC into an EOS-TC N/A N/A 6 4.00 0 0 0%

and prepare the EOS-TC for placement into the spent fuel pool.

2 Move the EOS-TC containing an EOS- 0%

DSC without fuel into the spent fuel N/A N/A 6 1.50 0 0 pool.

3 Remove a loaded EOS-TC from the 1.6%

fuel pool and place in the Decon. DRL1 2 0.25 101 50 decontamination area.

Refill neutron shield tank if necessary.

4 Decontaminate the EOS-TC and Decon. DRL2 2 1.75 315 1104 34.5%

prepare welds. Decon. DRL3 2 0.50 232 232 7.2%

5 Weld inner top cover plate. Welding DRL3 2 0.75 127 191 6.0%

6 Vacuum dry and backfill with helium. Welding DRL3 2 0.50 127 127 4.0%

7 Weld outer top cover plate and port covers, perform non-destructive Welding DRL3 2 0.50 127 127 4.0%

examination.

8 Drain annulus. Install EOS-TC top cover. Ready the support skid and Transfer DRL5 1 0.50 196 98 3.1%

transfer trailer.

9 Place the EOS-TC onto the skid and Transfer DRL2 2 0.33 248 164 5.1%

trailer. Secure the EOS-TC to the skid.

10 Install RRT. Transfer HMX 2 2.00 50 200 6.2%

Page A.11-14 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-3 Occupational Exposure, EOS-TC125/135 with EOS-37PTH DSC (2 Pages)

Dose  % of Dose Rate No. of Duration Dose Rate (person Total No. (2) Operation Configuration Location People (hr) (mrem/hr) -mrem) Dose 11 Transfer the EOS-TC to ISFSI. N/A N/A 6 1.83 0 0 0%

12 Position the EOS-TC inside the loading Transfer HMX+DRL2 2 0.50 298 298 9.3%

crane (MX-LC).

13 Remove forced cooling system (if used)

Transfer DRL9 2 0.50 76 76 2.4%

and install the ram cylinder assembly.

14 Remove HSM-MX door. Transfer HMX 2 0.50 50 50 1.6%

15 Remove the EOS-TC top cover. Transfer HMX+DRL6 2 0.67 108 145 4.5%

16 Align and dock the EOS-TC with the HSM-MX. Secure the EOS-TC to the Transfer HMX+DRL7 2 0.25 147 74 2.3%

HSM-MX.

17 Transfer the EOS-DSC from the EOS-TC to the HSM-MX using the ram N/A N/A 3 0.50 0 0 0%

cylinder.

18 Disengage the ram and un-dock Transfer HMX+DRL10 2 0.08 88 14 0.4%

the EOS-TC from the HSM-MX.

19 Install HSM-MX access door. Move EOS-TC to the transfer skid for Transfer HMX 2 0.50 50 50 1.6%

removal.

20 Uninstall RRT. Transfer HMX 2 2.00 50 200 6.2%

(1)

Total 3200 Note:

(1) Use of aluminum cask lid increases total occupational dose by approximately ~95 person-mrem.

(2) Occupational exposures for steps 1 through 9 are consistent with Chapter 11, Table 11-4.

Page A.11-15 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-4 Occupational Exposure, EOS-TC125 with EOS-89BTH DSC (2 Pages)

Dose  % of Dose Rate No. of Duration Dose Rate (person Total No.(1) Operation Configuration Location People (hr) (mrem/hr) -mrem) Dose 1 Drain neutron shield if necessary. Place an empty EOS-DSC into an EOS-TC N/A N/A 6 4.00 0 0 0%

and prepare the EOS-TC for placement into the spent fuel pool.

2 Move the EOS-TC containing an EOS-DSC without fuel into the spent fuel N/A N/A 6 1.50 0 0 0%

pool.

3 Remove a loaded EOS-TC from the fuel pool and place in the Decon. DRL1 2 0.25 62 31 1.2%

decontamination area. Refill neutron shield tank if necessary.

4 Decontaminate the EOS-TC and Decon. DRL2 2 1.75 181 634 25.1%

prepare welds. Decon. DRL3 2 0.50 98 98 3.9%

5 Weld inner top cover plate. Welding DRL3 2 0.75 113 170 6.7%

6 Vacuum dry and backfill with helium. Welding DRL3 2 0.50 113 113 4.5%

7 Weld outer top cover plate and port covers, perform non-destructive Welding DRL3 2 0.50 113 113 4.5%

examination.

8 Drain annulus. Install EOS-TC top cover. Ready the support skid and Transfer DRL5 1 0.50 191 96 3.8%

transfer trailer.

9 Place the EOS-TC onto the skid and Transfer DRL2 2 0.33 239 158 6.3%

trailer. Secure the EOS-TC to the skid.

10 Install RRT. Transfer HMX 2 2.00 50 200 7.9%

11 Transfer the EOS-TC to ISFSI. N/A N/A 6 1.83 0 0 0%

Page A.11-16 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-4 Occupational Exposure, EOS-TC125 with EOS-89BTH DSC (2 Pages)

Dose  % of Dose Rate No. of Duration Dose Rate (person Total No.(1) Operation Configuration Location People (hr) (mrem/hr) -mrem) Dose 12 Position the EOS-TC inside the loading Transfer HMX+DRL2 2 0.50 289 289 11.5%

crane (MX-LC).

13 Remove forced cooling system (if used)

Transfer DRL9 2 0.50 114 114 4.5%

and install the ram cylinder assembly.

14 Remove HSM-MX door. Transfer HMX 2 0.50 50 50 2.0%

15 Remove the EOS-TC top cover. Transfer HMX+DRL6 2 0.67 93 125 4.9%

16 Align and dock the EOS-TC with the HSM-MX. Secure the EOS-TC to the Transfer HMX+DRL7 2 0.25 141 71 2.8%

HSM-MX.

17 Transfer the EOS-DSC from the EOS-TC to the HSM-MX using the ram N/A N/A 3 0.50 0 0 0%

cylinder.

18 Disengage the ram and un-dock Transfer HMX+DRL10 2 0.08 88 14 0.6%

the EOS-TC from the HSM-MX.

19 Install HSM-MX access door. Move EOS-TC to the transfer skid for Transfer HMX 2 0.50 50 50 2.0%

removal.

20 Uninstall RRT. Transfer HMX 2 2.00 50 200 7.9%

(2)

Total 2523 Note:

(1) Occupational exposures for steps 1 through 9 are consistent with Chapter 11, Table 11-5.

(2) Use of an aluminum cask lid increases the total occupational exposure by approximately 70 person-mrem.

Page A.11-17 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-5 Total Annual Exposure from ISFSI 2x11 Two 1x11 Front Total Side Total Back Total Side Total Distance Dose Dose Dose Dose (m) (mrem) (mrem) (mrem) (mrem) 6.1 144687 12069 10042 58090 10 88673 9504 8176 30971 20 32767 5876 5366 11061 30 16063 4035 3807 5937 40 9324 2925 2826 3815 50 6007 2205 2157 2689 60 4137 1703 1679 1992 70 2979 1338 1331 1520 80 2221 1087 1071 1197 90 1698 867 869 961 100 1323 706 714 776 200 191 126 131 135 300 43 31 32 32 400 12 8 9 9 500 4 3 3 3 600 1 1 1 1 Page A.11-18 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-6 ISFSI Surface Sources 2x11 Back-to-Back Configuration Neutron Gamma Source Area (cm2) Source (n/s) Source (/s)

Roof 2.640E+06 2.157E+08 2.414E+11 Front 1 1.892E+06 1.145E+08 9.324E+10 Front 2 1.892E+06 1.145E+08 9.324E+10 Side 1 1.137E+06 8.005E+05 3.898E+08 Side 2 1.137E+06 8.005E+05 3.898E+08 Total 8.697E+06 4.464E+08 4.287E+11 Two 1x11 Front-to-Front Arrays (source for one of the two rows)

Neutron Gamma 2

Source Area (cm ) Source (n/s) Source (/s)

Roof 1.474E+06 1.205E+08 1.348E+11 Front 1.892E+06 1.145E+08 9.324E+10 Back 1.892E+06 1.195E+06 8.996E+08 Side 1 6.351E+05 4.470E+05 2.177E+08 Side 2 6.351E+05 4.470E+05 2.177E+08 Total 6.528E+06 2.371E+08 2.294E+11 Page A.11-19 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-7 2x11 Back-to-Back Dose Rates (2 Pages)

In Front of ISFSI Gamma Neutron Total Distance Dose Rate Dose Rate Dose Rate (m) (mrem/hr) (mrem/hr) (mrem/hr) 6.1 1.62E+01 3.58E-01 1.65E+01 0.02%

10 9.90E+00 2.21E-01 1.01E+01 0.03%

20 3.66E+00 8.23E-02 3.74E+00 0.05%

30 1.79E+00 4.05E-02 1.83E+00 0.1%

40 1.04E+00 2.32E-02 1.06E+00 0.1%

50 6.71E-01 1.46E-02 6.86E-01 0.1%

60 4.62E-01 9.84E-03 4.72E-01 0.2%

70 3.33E-01 6.88E-03 3.40E-01 0.1%

80 2.49E-01 4.97E-03 2.54E-01 0.2%

90 1.90E-01 3.74E-03 1.94E-01 0.2%

100 1.48E-01 2.87E-03 1.51E-01 0.2%

200 2.14E-02 4.23E-04 2.18E-02 0.3%

300 4.78E-03 1.18E-04 4.90E-03 0.7%

400 1.28E-03 4.74E-05 1.33E-03 1.2%

500 4.18E-04 1.87E-05 4.37E-04 4.9%

600 1.33E-04 6.57E-06 1.40E-04 1.6%

Page A.11-20 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-7 2x11 Back-to-Back Dose Rates (2 Pages)

At Side of ISFSI Gamma Neutron Total Distance Dose Rate Dose Rate Dose Rate (m) (mrem/hr) (mrem/hr) (mrem/hr) 6.1 1.31E+00 6.67E-02 1.38E+00 0.1%

10 1.03E+00 5.15E-02 1.08E+00 0.1%

20 6.42E-01 2.93E-02 6.71E-01 0.1%

30 4.43E-01 1.81E-02 4.61E-01 0.2%

40 3.22E-01 1.19E-02 3.34E-01 0.1%

50 2.43E-01 8.20E-03 2.52E-01 0.2%

60 1.89E-01 5.89E-03 1.94E-01 0.2%

70 1.48E-01 4.34E-03 1.53E-01 0.2%

80 1.21E-01 3.29E-03 1.24E-01 1.6%

90 9.65E-02 2.53E-03 9.90E-02 0.3%

100 7.85E-02 2.00E-03 8.05E-02 0.2%

200 1.40E-02 3.66E-04 1.44E-02 0.4%

300 3.40E-03 9.85E-05 3.50E-03 1.2%

400 9.26E-04 3.66E-05 9.62E-04 0.9%

500 2.92E-04 1.41E-05 3.06E-04 1.9%

600 9.88E-05 6.59E-06 1.05E-04 1.9%

Page A.11-21 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-8 Two 1x11 Front-to-Front Dose Rates (2 Pages)

In Back of ISFSI Gamma Neutron Total Distance Dose Rate Dose Rate Dose Rate (m) (mrem/hr) (mrem/hr) (mrem/hr) 6.1 1.09E+00 5.54E-02 1.15E+00 0.3%

10 8.89E-01 4.43E-02 9.33E-01 0.1%

20 5.86E-01 2.63E-02 6.13E-01 0.1%

30 4.18E-01 1.66E-02 4.35E-01 0.1%

40 3.11E-01 1.12E-02 3.23E-01 0.1%

50 2.39E-01 7.72E-03 2.46E-01 0.1%

60 1.86E-01 5.54E-03 1.92E-01 0.2%

70 1.48E-01 4.08E-03 1.52E-01 0.2%

80 1.19E-01 3.08E-03 1.22E-01 0.3%

90 9.68E-02 2.44E-03 9.92E-02 0.2%

100 7.96E-02 1.87E-03 8.15E-02 0.3%

200 1.46E-02 3.34E-04 1.50E-02 0.5%

300 3.53E-03 1.09E-04 3.63E-03 0.8%

400 1.01E-03 3.61E-05 1.05E-03 1.4%

500 3.17E-04 1.40E-05 3.31E-04 1.9%

600 1.11E-04 5.94E-06 1.17E-04 3.8%

Page A.11-22 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-8 Two 1x11 Front-to-Front Dose Rates (2 Pages)

At Side of ISFSI Gamma Neutron Total Distance Dose Rate Dose Rate Dose Rate (m) (mrem/hr) (mrem/hr) (mrem/hr) 6.1 6.46E+00 1.70E-01 6.63E+00 0.02%

10 3.44E+00 9.81E-02 3.54E+00 0.03%

20 1.22E+00 3.94E-02 1.26E+00 0.1%

30 6.56E-01 2.13E-02 6.78E-01 0.1%

40 4.22E-01 1.32E-02 4.36E-01 0.1%

50 2.98E-01 8.82E-03 3.07E-01 0.1%

60 2.21E-01 6.19E-03 2.27E-01 0.1%

70 1.69E-01 4.54E-03 1.74E-01 0.1%

80 1.33E-01 3.30E-03 1.37E-01 0.1%

90 1.07E-01 2.57E-03 1.10E-01 0.2%

100 8.66E-02 2.00E-03 8.86E-02 0.2%

200 1.50E-02 3.62E-04 1.54E-02 0.3%

300 3.55E-03 1.02E-04 3.65E-03 0.6%

400 9.99E-04 3.21E-05 1.03E-03 0.7%

500 3.21E-04 1.46E-05 3.36E-04 1.4%

600 1.06E-04 5.52E-06 1.12E-04 1.3%

Page A.11-23 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-9 2x11 Back-to-Back Accident Dose Rates (2 Pages)

In Front of ISFSI Gamma Neutron Total Distance Dose Rate Dose Rate Dose Rate (m) (mrem/hr) (mrem/hr) (mrem/hr) 6.1 5.74E+01 7.25E-01 5.81E+01 0.05%

10 4.11E+01 5.01E-01 4.16E+01 0.1%

20 2.18E+01 2.39E-01 2.20E+01 0.1%

30 1.40E+01 1.39E-01 1.41E+01 0.1%

40 9.80E+00 9.00E-02 9.89E+00 0.1%

50 7.25E+00 6.09E-02 7.32E+00 0.1%

60 5.56E+00 4.39E-02 5.60E+00 0.2%

70 4.36E+00 3.24E-02 4.39E+00 0.2%

80 3.48E+00 2.50E-02 3.51E+00 0.2%

90 2.82E+00 1.94E-02 2.84E+00 0.2%

100 2.30E+00 1.56E-02 2.32E+00 0.3%

200 4.19E-01 2.94E-03 4.22E-01 0.4%

300 1.03E-01 8.40E-04 1.04E-01 0.8%

400 2.91E-02 3.28E-04 2.94E-02 0.9%

500 8.83E-03 1.41E-04 8.97E-03 1.3%

600 2.92E-03 5.79E-05 2.98E-03 2.0%

Page A.11-24 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Table A.11-9 2x11 Back-to-Back Accident Dose Rates (2 Pages)

At Side of ISFSI Gamma Neutron Total Distance Dose Rate Dose Rate Dose Rate (m) (mrem/hr) (mrem/hr) (mrem/hr) 6.1 1.33E+02 7.31E-01 1.34E+02 0.04%

10 7.96E+01 4.72E-01 8.01E+01 0.1%

20 3.21E+01 2.16E-01 3.23E+01 0.1%

30 1.81E+01 1.25E-01 1.82E+01 0.4%

40 1.17E+01 8.07E-02 1.18E+01 0.1%

50 8.34E+00 5.60E-02 8.39E+00 0.1%

60 6.19E+00 4.04E-02 6.23E+00 0.1%

70 4.76E+00 3.04E-02 4.79E+00 0.2%

80 3.76E+00 2.34E-02 3.78E+00 0.2%

90 3.00E+00 1.84E-02 3.01E+00 0.2%

100 2.42E+00 1.46E-02 2.44E+00 0.2%

200 4.33E-01 2.95E-03 4.36E-01 0.4%

300 1.05E-01 8.18E-04 1.06E-01 0.7%

400 3.00E-02 3.02E-04 3.03E-02 1.1%

500 9.36E-03 1.36E-04 9.49E-03 2.1%

600 3.09E-03 5.60E-05 3.15E-03 1.6%

Page A.11-25 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.11-1 Total Annual Exposure from the ISFSI Page A.11-26 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.11-2 2x11 ISFSI MCNP Geometry Page A.11-27 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Figure A.11-3 Two 1x11 ISFSI MCNP Geometry Page A.11-28 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.12 ACCIDENT ANALYSES Table of Contents A.12 ACCIDENT ANALYSES ........................................................................................... A.12-1 A.12.1 Introduction .................................................................................................. A.12-1 A.12.2 Off-Normal Events ....................................................................................... A.12-2 A.12.2.1 Off-Normal Transfer Load .............................................................. A.12-2 A.12.2.2 Extreme Temperatures .................................................................... A.12-4 A.12.3 Postulated Accidents .................................................................................... A.12-5 A.12.3.1 EOS-TC Drop ................................................................................. A.12-5 A.12.3.2 Earthquake ...................................................................................... A.12-7 A.12.3.3 Tornado Wind and Tornado Missiles Effect on HSM-MX ............ A.12-7 A.12.3.4 Tornado Wind and Tornado Missiles Effect on EOS-TC ............... A.12-9 A.12.3.5 Flood ............................................................................................... A.12-9 A.12.3.6 Blockage of HSM-MX Air Inlet Openings ..................................... A.12-9 A.12.3.7 Lightning ....................................................................................... A.12-10 A.12.3.8 Fire/Explosion ............................................................................... A.12-10 A.12.4 References ................................................................................................... A.12-12 Page A.12-i Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.12 ACCIDENT ANALYSES A.12.1 Introduction No change to Section 12.1, except that this appendix is updated to include the NUHOMS MATRIX (HSM-MX).

Page A.12-1 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.12.2 Off-Normal Events Off-normal events are design events of the second type (Design Event II) as defined in ANSI/ANS 57.9 [A.12-2]. Design Event II conditions consist of a set of events that do not occur regularly, but can be expected to occur with a moderate frequency, or about once during a calendar year of independent spent fuel storage installation (ISFSI) operation.

For the HSM-MX, off-normal events could occur during trailer movement, EOS-37PTH dry shielded canister (DSC) or EOS-89BTH DSC transfer and other operational events. The two off-normal events, which bound the range of off-normal conditions, are:

A jammed DSC during loading or unloading from the HSM-MX The extreme ambient temperatures of -40 F (winter) and +117 F (summer)

These two events envelop the range of expected off-normal structural loads and temperatures acting on the HSM-MX.

A.12.2.1 Off-Normal Transfer Load Although unlikely, the postulated off-normal handling event assumes that the leading edge of the DSC becomes jammed against some element of the support structure during transfer between the EOS transfer cask (EOS-TC) and the HSM-MX.

Cause of Event It is postulated that if the EOS-TC is not accurately aligned with respect to the HSM-MX, may bind or jam the DSC during transfer operations.

The interiors of the EOS-TC and the HSM-MX are inspected prior to transfer operations to ensure there are no obstacles. Also, the DSC has beveled lead-ins on each end, designed to avoid binding or sticking on small (less than 0.25-inch) obstacles. The EOS-TC and the MATRIX retractable roller tray (MX-RRT) supports are designed to minimize binding or obstruction during DSC transfer. The postulated off-normal handling load event considers that the leading edge of the DSC becomes jammed against some element of the MX-RRT because of an unlikely gross misalignment of the EOS-TC.

The interfacing dimensions of the top end of the EOS-TC and the HSM-MX access opening sleeve are specified so that docking the EOS-TC with the HSM-MX is not possible should gross misalignments between the EOS-TC and HSM-MX exist.

Page A.12-2 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Detection of Event The normal load to push/pull the DSC in and out of the EOS-TC/HSM-MX is 135 kips and 80 kips, respectively, applied at the grapple ring and resisted by an axial load of 70 kips push and 40 kips pull on each of the MX-RRT. This movement is performed at a very low speed. System operating procedures and technical specification limits defining the safeguards to be provided ensure that the system design margins are not compromised. If the DSC were to jam or bind during transfer, the pressure increases. The off-normal load set for the jammed DSC for both insertion and retrieval are 135 kips and 80 kips, respectively. This load is administratively controlled to ensure that during the transfer operation this load is not exceeded.

During the transfer operation, the force exerted on the DSC by the ram is that required to first overcome the static frictional resisting force between the EOS-TC rails and the MX-RRT rollers. Once the DSC begins to slide on the rollers, the resisting force is a function of sliding friction between the DSC and the EOS-TC rails or between the DSC and the MX-RRT. If motion is prevented, the pressure increases, thereby increasing the force on the DSC until the ram system pressure limit is reached. This limit is controlled so that adequate force is available but is sufficiently low to ensure that component damage does not occur.

Analysis of Effects and Consequences The DSC and the HSM-MX are designed and analyzed for off-normal transfer loads of 135 kips for insertion and 80 kips for retrieval during insertion and retrieval (unloading) operations. These analyses are discussed in Appendix A.3.9.1 for DSC and A.3.9.4 for HSM-MX. For either loading or unloading of the DSC under off-normal conditions, the stresses on the shell assembly components are demonstrated to be within the ASME allowable stress limits. Therefore, permanent deformation of the DSC shell components does not occur. The internal basket assembly components are unaffected by these loads based on clearances provided between the basket and DSC internal cavity.

There is no breach of the confinement pressure boundary and, therefore, no potential for release of radioactive material exists.

Corrective Actions No changes to corrective actions described in Section 12.2.1.

Page A.12-3 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.12.2.2 Extreme Temperatures The HSM-MX is designed for use at ambient temperatures of -40 °F (winter) and 117

°F (summer). Even though these extreme temperatures are likely to occur for a short period of time, it is conservatively assumed that these temperatures occur for a sufficient duration to produce steady state temperature distributions in HSM-MX.

Each licensee should verify that this range of ambient temperatures envelopes the design basis ambient temperatures for the ISFSI site. The components affected by the postulated extreme ambient temperatures are the EOS-TC and DSC during their transfer from the plant's fuel/reactor building to the ISFSI site, and the HSM-MX during storage of a DSC.

Cause of Event Off-normal ambient temperatures are natural phenomena.

Detection of Event Off-normal ambient temperature conditions are confirmed by the licensee to be bounding for their site.

Analysis of Effects and Consequences The thermal evaluation of the HSM-MX for extreme ambient conditions is presented in Chapter A.4. The effects of extreme ambient temperatures on the NUHOMS MATRIX System are analyzed in sections as follows:

Components UFSAR Sections EOS-37PTH DSC and EOS-89BTH DSC Shell Appendix 3.9.1 and A.3.9.1 EOS-37PTH Basket and EOS-89BTH Basket Appendix 3.9.2 HSM-MX Appendix A.3.9.4 & A.3.9.7 EOS-TC Appendix 3.9.5 Corrective Actions None Page A.12-4 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.12.3 Postulated Accidents The design basis accident events specified by ANSI/ANS 57.9-1984 [A.12-2] and other postulated accidents that may affect the normal safe operation of the HSM-MX are addressed in this section.

The following sections provide descriptions of the analyses performed for each accident condition. The analyses demonstrate that the requirements of 10 CFR 72.122

[A.12-1] are met and that adequate safety margins exist for the HSM-MX System design. The resulting accident condition stresses in the HSM-MX components are evaluated and compared with the applicable code limits set forth in Chapter A.2.

Radiological calculations are performed to confirm that on-site and off-site dose rates are within acceptable limits. Similarly seismic calculations are performed to confirm that seismic stresses are within acceptable stress limits.

The postulated accident conditions addressed in this section include:

EOS-TC drop Earthquake Tornado wind pressure and tornado-generated missiles Flood Blockage of HSM-MX air inlet openings Lightning Fire/Explosion A.12.3.1 EOS-TC Drop Cause of Accident As described in Chapter A.9, handling operations involving hoisting and movement of EOS-TC loaded with the EOS-37PTH or EOS-89BTH DSC is typically performed inside the plants fuel handling building. These include utilizing the crane for placement of the empty DSC into the EOS-TC cavity, lifting the EOS-TC/DSC onto the transfer skid/trailer. An analysis of the plants lifting devices used for these operations, including the crane and lifting yoke, is needed to address a postulated drop accident for the EOS-TC and its contents. The postulated drop accident scenarios addressed in the plants 10 CFR Part 50 [A.12-3] licensing basis are plant-specific and should be addressed by the licensee.

Page A.12-5 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Once the EOS-TC is loaded onto the transfer skid/trailer and secured, it is pulled to the HSM-MX site by a tractor vehicle. A predetermined route is chosen to minimize the potential hazards that could occur during transfer. This movement is performed at very low speeds. System operating procedures and technical specification limits defining the safeguards to be provided ensure that the system design margins are not compromised. As a result, it is highly unlikely that any plausible incidents leading to an EOS-TC drop accident could occur. At the ISFSI site, the transfer skid/trailer is used in conjunction with the MATRIX loading crane (MX-LC). The MX-LC is used to assist in loading the DSC into the HSM. The MX-LC is designed, fabricated, installed, tested, inspected and qualified in accordance with ASME NOG-1, as a Type I gantry type of crane, as per the guidance provided in NUREG-0612 [A.12-4]. The transfer skid/trailer is backed up to, and aligned with, the HSM-MX using transfer equipment. The EOS-TC/MX-LC is docked with, and secured to, the HSM-MX access opening. The MX-RRT rollers are extended into HSM-MX through front wall slots for the MX-RRT and secured. The loaded DSC is transferred to or from the HSM-MX using a transfer equipment. The MX-RRT is then lowered to place the DSC on the front and rear DSC supports in the HSM-MX. As a result, for a loaded EOS-TC drop accident to occur during these operations is considered non credible.

Lifts of the EOS-TC loaded with the dry storage canister are made within the existing heavy loads requirements and procedures of the licensed nuclear power plant. The EOS-TC design meets requirements of NUREG-0612 [A.12-4] and American National Standards Institute (ANSI) N14.6 [A.12-4].

The EOS-TC is transferred to the ISFSI in a horizontal configuration. Therefore, the only drop accident evaluated during storage or transfer operations is a side drop or a corner drop.

The EOS-TC and DSC are evaluated for a postulated side and corner drops to demonstrate structural integrity during transfer and plant handling.

Accident Analysis No change to accident analysis in Section 12.3.1.

Accident Dose Calculation No change to the accident dose calculation described in Section 12.3.1.

Corrective Actions No change to corrective actions described in Section 12.3.1.

Page A.12-6 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.12.3.2 Earthquake Cause of Accident The explicitly evaluated seismic response spectra for the NUHOMS HSM-MX consist of the U.S. Nuclear Regulatory Commission (NRC) Regulatory Guide 1.60 (Reg. Guide 1.60) [A.12-6] with enhanced spectral accelerations above 9 Hz, and anchored to a maximum ground acceleration of 0.85g horizontal and 0.80g for the vertical peak accelerations. The results of the frequency analysis of the HSM-MX structure (which includes a simplified model of the DSC) yield a lowest frequency of 23.94 Hz in the transverse direction and 24.08 Hz in the longitudinal direction. The lowest vertical frequency is 49.02 Hz. Thus, based on the Reg. Guide 1.60 response spectra amplifications, the corresponding seismic accelerations used for the design of the HSM-MX are 1.33g and 1.33g in the transverse and longitudinal directions, respectively, and 0.80g in the vertical direction. The corresponding accelerations applicable to the DSC are 1.62g and 1.61g in the transverse and longitudinal directions, respectively, and 0.80g in the vertical direction.

Accident Analysis The seismic analyses of the components that are important to safety are analyzed as follow:

Components UFSAR Sections EOS-37PTH DSC and EOS-89BTH DSC Shell Appendix 3.9.1 and A.3.9.1 EOS-37PTH Basket and EOS-89BTH Basket Appendix 3.9.2 HSM-MX Appendices A.3.9.4 & A.3.9.7 EOS-TC Appendix 3.9.5 The results of these analyses show that seismic stresses are well below the applicable stress limits.

Accident Dose Calculations The dose rate increase is bounded by Section A.12.3.3.

Corrective Actions No change to corrective actions described in Section 12.3.2.

A.12.3.3 Tornado Wind and Tornado Missiles Effect on HSM-MX Cause of Accident No change to the cause of accident described in Section 12.3.3.

Page A.12-7 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Accident Analysis Stability and stress analyses are performed to determine the response of the HSM-MX to flood, massive missile impact and tornado wind pressure loads.

The stress analyses are performed using the ANSYS [A.12-7]. HSM-MX storage modules arranged in a back-to-back row array provides a conservative estimate of the response of the HSM-MX under postulated static and dynamic loads for any HSM-MX array configurations. These analyses are described in Appendix A.3.9.4.

The sliding and overturning stability analyses due to wind, flood and massive impact loads are performed using closed-form calculation methods to determine the sliding and overturning response of the HSM-MX. A non-linear seismic stability analysis is performed using LS-DYNA [A.12-8]. These analyses are described in Appendix A.3.9.7, Section A.3.9.7.1.

Thus, the requirements of 10 CFR 72.122 are met.

Accident Dose Calculation As discussed in the evaluations, the tornado wind and tornado missiles do not breach the HSM-MX to the extent that the DSC confinement boundary is compromised.

Localized scabbing of the end shield wall of a HSM-MX array may be possible.

When the array is in the expansion configuration with the removable end shield wall absent, two inner walls may be damaged as a result of a missile impact.

The HSM-MX outlet vent covers and all dose reduction hardware (DRH) may be lost due to a tornado or tornado missile event. The assumed accident damage increases the dose rates on the front, roof, and end (side) of the HSM-MX. The effect on the average rear dose rate is negligible because the rear surface does not contain vents and sustains little damage in an accident. The HSM-MX accident increases the average dose rate on the front, roof, and end of the module to 92.9 mrem/hr, 4,730 mrem/hr, and 425 mrem/hr, respectively (see Section A.6.1).

The evaluation for the impact on public exposure, a 2x11 ISFSI configuration and a distance to the site boundary of 349 m is used. As documented in Chapter A.11, Section A.11.3.2, for a 2x11 ISFSI configuration, the accident dose rate is approximately 0.436 mrem/hour and 0.061 mrem/hr at a distance of 200 m and 349 m, respectively, from the ISFSI. It is assumed that the recovery time for this accident is five days (120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br />). Therefore, the total exposure to an individual at a distance of 200 m and 349 m is 52 mrem and 7.3 mrem, respectively. This is significantly less than the 10 CFR 72.106 limit of 5 rem. Note that the dose is bounded by the EOS-HSM accident dose documented in Section 12.3.3.

Corrective Action No change to corrective actions described in Section 12.3.3.

Page A.12-8 Appendix A is newly added in Revision 3 by Amendment 1.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.12.3.4 Tornado Wind and Tornado Missiles Effect on EOS-TC Cause of Accident No change to cause of accident described in Section 12.3.4.

Accident Analysis No change to accident analysis described in Section 12.3.4.

Accident Dose Calculation No change to accident dose calculation described in Section 12.3.4.

Corrective Actions No change to corrective actions described in Section 12.3.4.

A.12.3.5 Flood Cause of Accident This event is described in Section 12.3.5.

Accident Analysis The HSM-MX is evaluated for flooding in Appendix A.3.9.4. Based on the evaluation presented in that section, the HSM-MX can withstand the design basis flood.

Accident Dose Calculation No change to accident dose calculation described in Section 12.3.5.

Corrective Actions No change to corrective actions described in Section 12.3.5.

A.12.3.6 Blockage of HSM-MX Air Inlet Openings This accident conservatively postulates the complete blockage of the air inlet openings of the HSM-MX.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Cause of Accident Since the HSM-MX is located outdoors, there is a remote probability that the air inlet or outlet openings could become blocked by debris from such unlikely events as floods and tornadoes. There are no credible scenarios that could block both the inlet and outlet vents at the same time due to the significant height difference between the inlet and out vent locations. Therefore, only blockage of the inlet vents is considered in the UFSAR. The HSM-MX design features, such as the perimeter security fence and the redundant protected location of the air inlet and outlet openings, reduce the probability of occurrence of such an accident. Nevertheless, for this conservative generic analysis, such an accident is postulated to occur and is analyzed.

Accident Analysis The thermal evaluation of this event is presented in Chapter A.4, Section A.4.5 for the EOS-37PTH DSC stored inside an HSM-MX. The analysis performed for the EOS-37PTH DSC bounds the values for the EOS-89BTH DSC. Therefore, the temperatures determined for Load Case #3-S in Section A.4.5 are used in the HSM-MX structural evaluation of this event. The HSM-MX structural analysis, presented in Appendix A.3.9.4, demonstrates that the HSM-MX component stresses remain below allowable values.

Accident Dose Calculation There are no offsite dose consequences as a result of this accident.

Corrective Actions No change to corrective actions described in Section 12.3.6.

A.12.3.7 Lightning Cause of Accident No change to cause of accident described in Section 12.3.7.

Accident Analysis No change to accident analysis described in Section 12.3.7.

Corrective Actions No change to corrective actions described in Section 12.3.7.

A.12.3.8 Fire/Explosion Cause of Accident No change to cause of accident described in Section 12.3.8.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 Accident Analysis No change to accident analysis described in Section 12.3.8.

Accident Dose Calculation No change to the accident dose calculation described in Section 12.3.8.

Corrective Actions No change to corrective actions described in Section 12.3.8.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 A.12.4 References A.12-1 Title 10, Code of Federal Regulations, Part 72, Licensing Requirements for the Independent Storage of Spent Nuclear Fuel, High-Level Radioactive Waste, and Reactor-Related Greater than Class C Waste.

A.12-2 ANSI/ANS-57.9-1984, Design Criteria for an Independent Spent Fuel Storage Installation (Dry Storage Type), American National Standards Institute, American Nuclear Society.

A.12-3 Title 10, Code of Federal Regulations, Part 50, Domestic Licensing of Production and Utilization Facilities.

A.12-4 NUREG-0612, Control of Heavy Loads at Nuclear Power Plants, U.S. Nuclear Regulatory Commission, July 1980.

A.12-5 ANSI N14.6-1993, American National Standards for Special Lifting Device for Shipping Containers Weighing 10,000 lbs. or More for Nuclear Materials, American National Standards Institute.

A.12-6 U.S. Nuclear Regulatory Commission, Regulatory Guide 1.60, Design Response Spectra for Seismic Design of Nuclear Power Plants, U.S. Atomic Energy Commission, Revision 1, December 1973.

A.12-7 ANSYS Computer Code and Users Manual, Release 14.0 and 17.1.

A.12-8 LS-DYNA Version 7.0.0, Rev. 79055, Livermore Software Technology Corporation (LSTC)

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.13 OPERATING CONTROLS AND LIMITS The operating controls and limits, including those for the NUHOMS MATRIX are described in Chapter 13.

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NUHOMS EOS System Updated Final Safety Analysis Report Rev. 3, 06/20 APPENDIX A.14 QUALITY ASSURANCE The addition of the NUHOMS MATRIX to the NUHOMS EOS system does not require any changes to the quality assurance requirements stipulated in Chapter 14.

Chapter 14 provides the Quality Assurance Program applied to the design, purchase, fabrication, handling, shipping, storing, cleaning, assembly, inspection, testing, operation, maintenance, repair, and modification of the NUHOMS EOS System and components identified as important-to-safety and safety-related.

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