ML20335A083

Independent Spent Fuel Storage Installation - Revision 28 to Updated Safety Analysis Report, Chapter 13, NUHOMS-32P Dry Shielded Canister

ML20335A083
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Site:	Calvert Cliffs
Issue date:	11/18/2020
From:	Exelon Generation Co
To:	Office of Nuclear Material Safety and Safeguards
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CHAPTER 13 NUHOMS-32PHB DRY SHIELDED CANISTER LIST OF EFFECTIVE PAGES PAGE REVISION PAGE REVISION LEP 13-1 27 13.8-3 26 13-i 26 13.8-4 26 13-ii 26 13.8-5 26 13-iii 26 13.8-6 26 13-iv 26 13.8-7 26 13-v 26 13.8-8 26 13-vi 26 13.8-9 26 13.1-1 26 13.8-10 26 13.2-1 26 13.8-11 26 13.3-1 26 13.8-12 26 13.3-2 26 13.8-13 27 13.3-3 26 13.8-14 26 13.3-4 26 13.8-15 26 13.3-5 26 13.8-16 26 13.3-6 26 13.8-17 26 13.3-7 26 13.8-18 26 13.3-8 26 13.8-19 26 13.3-9 26 13.8-20 26 13.3-10 26 13.8-21 27 13.3-11 26 13.8-22 27 13.3-12 26 13.8-23 26 13.3-13 26 13.8-24 26 13.3-14 26 13.8-25 26 13.3-15 26 13.8-26 26 13.3-16 26 13.8-27 26 13.3-17 27 13.8-28 26 13.3-18 26 13.8-29 26 13.3-19 26 13.9-1 26 13.3-20 26 13.10-1 26 13.3-21 26 13.11-1 26 13.3-22 26 13.12-1 26 13.3-23 26 13.13-1 26 13.4-1 26 13.13-2 26 13.5-1 26 13.13-3 26 13.6-1 26 13.13-4 26 13.7-1 26 Figure 13.3-1 26 13.7-2 26 13.7-3 26 13.7-4 26 13.7-5 26 13.7-6 26 13.7-7 26 13.7-8 26 13.7-9 26 13.7-10 26 13.8-1 26 13.8-2 26 CALVERT CLIFFS ISFSI USAR LEP 13-1 Rev. 27

CHAPTER 13 NUHOMS-32P DRY SHIELDED CANISTER TABLE OF CONTENTS PAGE 13.0 NUHOMS-32PHB DRY SHIELDED CANISTER 13.1-1

13.1 INTRODUCTION

AND GENERAL DESCRIPTION OF INSTALLATION 13.1-1 13.2 SITE CHARACTERISTICS 13.2-1 13.3 PRINCIPAL DESIGN CRITERIA 13.3-1 13.3.1 PURPOSE OF THE CALVERT CLIFFS INDEPENDENT 13.3-1 SPENT FUEL STORAGE INSTALLATION 13.3.2 STRUCTURAL AND MECHANICAL SAFETY CRITERIA 13.3-1 13.3.2.1 Tornado Wind and Tornado-Generated Missile 13.3-1 Loadings 13.3.2.2 Water Level (Flood) Design 13.3-1 13.3.2.3 Seismic Design 13.3-1 13.3.2.4 Snow and Ice Loadings 13.3-2 13.3.2.5 Combined Load Criteria 13.3-2 13.3.2.6 Weld Requirements 13.3-3 13.3.3 SAFETY PROTECTION SYSTEMS 13.3-4 13.3.3.1 General 13.3-4 13.3.3.2 Protection by Multiple Confinement Barriers and 13.3-4 Systems 13.3.3.3 Protection by Equipment and Instrumentation 13.3-5 Selection 13.3.3.4 Nuclear Criticality Safety 13.3-5 13.3.3.5 Radiation Protection 13.3-10 13.3.3.6 Fire and Explosions Protection 13.3-11 13.3.3.7 Materials Handling and Storage 13.3-11 13.3.3.8 Industrial and Chemical Safety 13.3-11 13.3.4 CLASSIFICATION OF STRUCTURES, COMPONENTS, 13.3-11 AND SYSTEMS 13.3.5 DECOMMISSIONING CONSIDERATIONS 13.3-11 13.3.6

SUMMARY

OF DESIGN CRITERIA 13.3-12 13.4 INSTALLATION DESIGN 13.4-1 13.5 OPERATION SYSTEMS 13.5-1 13.6 SITE GENERATED WASTE CONFINEMENT AND MANAGEMENT 13.6-1 CALVERT CLIFFS ISFSI USAR 13-i Rev. 26

CHAPTER 13 NUHOMS-32P DRY SHIELDED CANISTER TABLE OF CONTENTS PAGE 13.7 RADIATION PROTECTION 13.7-1 13.7.1 ENSURING THAT THE OCCUPATIONAL RADIATION 13.7-1 EXPOSURES ARE AS LOW AS REASONABLY ACHIEVABLE 13.7.1.1 Policy Considerations 13.7-1 13.7.1.2 Design Considerations - NUHOMS-32P DSC 13.7-1 13.7.1.3 Operational Considerations 13.7-3 13.7.2 RADIATION SOURCES - NUHOMS-32PHB 13.7-3 13.7.2.1 Characterization of Sources 13.7-3 13.7.2.2 Airborne Radioactive Material Sources 13.7-4 13.7.3 RADIATION PROTECTION DESIGN FEATURES - 13.7-4 NUHOMS-32PHB DSC 13.7.3.1 Installation Design Features 13.7-4 13.7.3.2 Shielding 13.7-4 13.7.3.3 Ventilation 13.7-4 13.7.3.4 Area Radiation and Airborne Radioactivity 13.7-5 Monitoring Instrumentation 13.7.4 ESTIMATED ON-SITE COLLECTIVE DOSE ASSESSMENT 13.7-5 13.7.4.1 Operational Exposure 13.7-5 13.7.4.2 Storage Term Exposure 13.7-5 13.7.5 HEALTH PHYSICS PROGRAM 13.7-5 13.7.6 ESTIMATED OFF-SITE COLLECTIVE DOSE 13.7-5 ASSESSMENT 13.7.6.1 Effluent and Environmental Monitoring Program 13.7-5 13.7.6.2 Analysis of Multiple Contribution 13.7-5 13.7.6.3 Estimated Dose Equivalents 13.7-5 13.7.6.4 Liquid Release 13.7-5 13.8 ACCIDENT ANALYSIS - NUHOMS-32PHB DSC 13.8-1 13.8.1 NORMAL AND OFF-NORMAL OPERATIONS 13.8-1 13.8.1.1 Normal Operation Structural Analysis 13.8-1 13.8.1.2 Off-Normal Load Structural Analysis 13.8-6 13.8.1.3 Thermal Hydraulic Analyses 13.8-8 CALVERT CLIFFS ISFSI USAR 13-ii Rev. 26

CHAPTER 13 NUHOMS-32P DRY SHIELDED CANISTER TABLE OF CONTENTS PAGE 13.8.2 ACCIDENTS 13.8-12 13.8.2.1 Loss of Air Outlet Shielding 13.8-13 13.8.2.2 Tornado Winds/Tornado Missile 13.8-13 13.8.2.3 Earthquake 13.8-13 13.8.2.4 Flood 13.8-16 13.8.2.5 Cask Drop 13.8-16 13.8.2.6 Lightning 13.8-21 13.8.2.7 Blockage of Air Inlets and Outlets 13.8-21 13.8.2.8 Dry Shielded Canister Leakage 13.8-22 13.8.2.9 Accidental Pressurization of Dry Shielded 13.8-22 Canister 13.8.2.10 Forest Fire 13.8-23 13.8.2.11 Liquified Natural Gas Plant or Pipeline Spill or 13.8-24 Explosion 13.8.2.12 Load Combinations 13.8-25 13.8.2.13 Other Event Considerations 13.8-25 13.8.3 SITE CHARACTERISTICS AFFECTING SAFETY 13.8-25 ANALYSIS 13.9 CONDUCT OF OPERATIONS 13.9-1 13.10 OPERATING CONTROLS AND LIMITS 13.10-1 13.11 QUALITY ASSURANCE 13.11-1 13.12 NOT USED 13.12-1 13.13 REFERENCES 13.13-1 CALVERT CLIFFS ISFSI USAR 13-iii Rev. 26

CHAPTER 13 NUHOMS-32P DRY SHIELDED CANISTER LIST OF TABLES TABLE PAGE 13.3-1 NUHOMS-32PHB DRY SHIELDED CANISTER DIMENSIONS 13.3-13 13.3-2 DESIGN PARAMETERS FOR CRITICALITY ANALYSIS OF 13.3-14 THE NUHOMS-32PHB DSC 13.3-3 NUHOMS-32PHB DSC

SUMMARY

OF DESIGN CRITERIA 13.3-16 FOR NORMAL OPERATING CONDITIONS 13.3-4 NUHOMS-32PHB DSC

SUMMARY

OF DESIGN 13.3-19 PARAMETERS FOR OFF-NORMAL OPERATING CONDITIONS 13.3-5 NUHOMS-32PHB DSC

SUMMARY

OF DESIGN CRITERIA 13.3-20 FOR ACCIDENT CONDITIONS 13.3-6 NUHOMS-32PHB DSC DESIGN LOAD COMBINATIONS 13.3-23 13.7-1 NUHOMS-32PHB SHIELDING ANALYSIS RESULTS - 13.7-6 MAXIMUM DOSE RATES (mrem/hr) 13.7-2 NEUTRON SOURCE TERMS (Neutron/Sec) (BOUNDING FOR 13.7-7 NUHOMS-32PHB DSC IN THE HSM-HB AND THE TRANSFER CASK) 13.7-3 GAMMA SOURCE TERMS FOR 1.0 kW (BOUNDING FOR 13.7-9 NUHOMS-32PHB DSC IN THE HSM-HB AND THE TRANSFER CASK) 13.7-4 GAMMA SOURCE TERMS FOR 0.8 kW (BOUNDING FOR 13.7-10 NUHOMS-32PHB DSC IN THE HSM-HB AND THE TRANSFER ASK) 13.8-1 NUHOMS-32PHB DRY SHIELDED CANISTER ENVELOPING 13.8-26 LOAD COMBINATION RESULTS FOR NORMAL AND OFF-NORMAL LOADS (ASME Service Levels A and B) 13.8-2 NUHOMS-32PHB DRY SHIELDED CANISTER ENVELOPING 13.8-27 LOAD COMBINATION RESULTS FOR ACCIDENT LOADS (ASME Service Level C) 13.8-3 NUHOMS-32PHB DRY SHIELDED CANISTER ENVELOPING 13.8-28 LOAD COMBINATION RESULTS FOR ACCIDENT LOADS (ASME Service Level D) 13.8-4 NUHOMS-32PHB DRY SHIELDED CANISTER SUPPORT 13.8-29 ASSEMBLY ENVELOPING LOAD COMBINATION RESULTS CALVERT CLIFFS ISFSI USAR 13-iv Rev. 26

CHAPTER 13 NUHOMS-32P DRY SHIELDED CANISTER LIST OF FIGURES FIGURE 13.3-1 HEAT LOAD ZONE CONFIGURATION FOR THE MAXIMUM HEAT LOAD IN A NUHOMS-32PHB CALVERT CLIFFS ISFSI USAR 13-v Rev. 26

CHAPTER 13 NUHOMS-32P DRY SHIELDED CANISTER LIST OF ACRONYMS ACI American Concrete Institute AISC American Institute of Steel Construction ANSI American National Standards Institute ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials B&PV Boiler and Pressure Vessel CCNPP Calvert Cliffs Nuclear Power Plant CE Combustion Engineering, Inc.

CFR Code of Federal Regulations CSAS5 Criticality Safety Analysis Sequence No. 5 DSC Dry Shielded Canister HSM Horizontal Storage Module HSM-HB High Burnup Horizontal Storage Module ISFSI Independent Spent Fuel Storage Installation ISG Interim Staff Guidance NRC Nuclear Regulatory Commission NUHOMS Nutech Horizontal Modular Storage USAR Updated Safety Analysis Report USL Upper Subcriticality Limit VAP Value Added Pellet CALVERT CLIFFS ISFSI USAR 13-vi Rev. 26

13.0 NUHOMS-32PHB DRY SHIELDED CANISTER An evaluation of the Nutech Horizontal Modular Storage (NUHOMS)-32PHB Dry Shielded Canister (DSC) used in the NUHOMS dry storage system is presented in this chapter. Updated Safety Analysis Report (USAR) Chapter 1 is revised to include information for the NUHOMS-24P, NUHOMS-32P, and NUHOMS-32PHB DSCs. Updated Safety Analysis Report Chapters 2 through 11 primarily apply to the NUHOMS-24P DSC, USAR Sections 12.2 through 12.11 provide the same information as it applies to the NUHOMS-32P DSC and USAR Sections 13.2 through 13.11 provide similar information as it applies to the NUHOMS-32PHB DSC.

General references are identified throughout the body of this chapter, and are listed in USAR Section 13.13. General references are intended to provide background information or additional detail that the reader may refer to in order to learn more about a particular topic presented in this document, but are not considered part of the Calvert Cliffs Nuclear Power Plant (CCNPP)

Independent Spent Fuel Storage Installation (ISFSI) USAR. A referenced document shall be considered to be a part of the USAR only if it is clearly annotated as being incorporated by reference in Chapter 13 of this report. Documents that are incorporated by reference are subject to the same administrative controls and regulatory requirements as the USAR.

13.1 INTRODUCTION

AND GENERAL DESCRIPTION OF INSTALLATION The introduction and general description of the NUHOMS-32PHB DSC and the horizontal storage module-high burnup model (HSM-HB) is integrated into Chapter 1.

CALVERT CLIFFS ISFSI USAR 13.1-1 Rev. 26

13.2 SITE CHARACTERISTICS The CCNPP ISFSI site characteristics are discussed in Chapter 2. The evaluation presented in Chapter 2 encompasses discussion of the NUHOMS-32PHB DSC and the associated modular constructed HSM-HB as part of the NUHOMS system used at CCNPP.

CALVERT CLIFFS ISFSI USAR 13.2-1 Rev. 26

13.3 PRINCIPAL DESIGN CRITERIA 13.3.1 PURPOSE OF THE CALVERT CLIFFS INDEPENDENT SPENT FUEL STORAGE INSTALLATION Information contained in USAR Section 3.1 is applicable to the NUHOMS-32PHB DSC and the HSM-HB.

13.3.2 STRUCTURAL AND MECHANICAL SAFETY CRITERIA Compared to the existing NUHOMS-24P DSC, the main difference in the principal design parameters for the NUHOMS-32PHB DSC, as in the case for the NUHOMS-32P DSC, consists of an increase in canister weight, radiological source, and decay heat due to the addition of eight more fuel assemblies, higher burnup fuel, and modifications to the DSC basket assembly. The NUHOMS-32P and NUHOMS-32PHB DSCs are very similar in design. The major differences between the two DSCs are the solid aluminum rails used to support the NUHOMS-32PHB DSC fuel basket, and the higher minimum B10 areal density of the NUHOMS-32PHB DSC poison plates (Reference 13.42).

As discussed in Reference 3.1, the NUHOMS transfer cask design was evaluated to ensure that a design basis tornado missile would not breach the DSC pressure boundary or jeopardize the health and safety of the public. The transfer cask was modified for handling forced cooling.

The NUHOMS-32PHB DSC is handled, loaded, and sealed in a similar manner to the NUHOMS-24P and NUHOMS-32P DSCs before being transported to the ISFSI. The transport to the ISFSI is done utilizing the self-propelled modular transporter. At the ISFSI, due to high burnup fuel characteristics, the NUHOMS-32PHB DSC is stored in a modular constructed HSM-HB and will not be placed into one the original poured in place HSMs. The environmental conditions and natural phenomena for a NUHOMS -32PHB DSC are the same as those described in USAR Section 3.2 and differences are as noted below.

13.3.2.1 Tornado Wind and Tornado-Generated Missile Loadings The tornado wind and tornado-generated missile loading criteria are described in USAR Section 3.2.1. They are based on Reference 12.21, which applies to the NUHOMS-24P DSC, but are applicable to the NUHOMS-32PHB DSC as well.

Evaluation of the NUHOMS-32PHB DSC for tornado wind and tornado-generated missiles is presented in USAR Section 13.8.2.2.

13.3.2.2 Water Level (Flood) Design As stated in USAR Section 3.2.2, the CCNPP ISFSI is not subject to flooding.

Therefore, the type of DSC and horizontal storage module HSM/HSM-HB used is independent of the flood water level.

13.3.2.3 Seismic Design For the HSM-HB, the principal seismic loading criteria are those corresponding to the HSM-H design (Reference 13.36) and are more conservative than those described in Section 3.2.3 for the HSM. The CALVERT CLIFFS ISFSI USAR 13.3-1 Rev. 26

HSM-HB seismic criteria were derived using the same basis as the HSM (Nuclear Regulatory Commission Regulatory Guides 1.60 and 1.61). The seismic loading criteria are described in Section 3.2.3.

Evaluation for the use of the NUHOMS-32PHB DSCs for seismic loading is presented in USAR Section 13.8.2.3.

13.3.2.4 Snow and Ice Loadings The snow and ice load analysis methodology and results for a transfer cask loaded with a NUHOMS-32PHB or NUHOMS-24P DSCs are the same, and are described in USAR Section 3.2.4.

The results for the modular constructed HSM-HB snow and its loading analysis are provided in Reference 13.10, Section 7.1 (Live Loads).

13.3.2.5 Combined Load Criteria 13.3.2.5.1 HSM-HB The CCNPP site-specific load combinations matrix and design criteria for the modular constructed HSM-HB storing the NUHOMS-32PHB DSC is presented in Section 3.2.5.1 and Table 3.2-2.

Structural evaluation of the modular constructed HSM-HB for the NUHOMS-32PHB DSC is presented in USAR Section 13.8.

13.3.2.5.2 NUHOMS-32PHB DSC The CCNPP site-specific load combinations for the NUHOMS-32PHB DSC are presented in USAR Table 13.3-6.

Structural evaluation of the NUHOMS-32PHB DSC basket assembly is presented in USAR Section 13.8.

13.3.2.5.3 NUHOMS Transfer Cask The same transfer cask is used for the NUHOMS-32P and NUHOMS-24P DSCs. The transfer cask is modified for the NUHOMS-32PHB to allow for forced cooling as needed.

The CCNPP site-specific load combinations and allowable stress criteria for the transfer cask are the same as those presented in USAR Section 3.2.5.3.

Structural evaluation of the transfer cask for the NUHOMS-32PHB DSC is presented in USAR Section 13.8.

13.3.2.5.4 System Transfer Equipment The load combinations and acceptance criteria for the transfer equipment are not affected by the use of the CALVERT CLIFFS ISFSI USAR 13.3-2 Rev. 26

NUHOMS-32PHB DSC and are the same as those in Section 3.2.5.4.

13.3.2.6 Weld Requirements DSC Shell and Basket Assembly Welds The NUHOMS-32PHB DSC shell assembly welded joint details are the same as for the NUHOMS-32P DSC shell assembly and are presented in References 13.48 through 13.57. The DSC welds are evaluated in Reference 12.22, Appendix A. The welds are re-evaluated based on the design allowables given in Reference 13.2 and Reference 13.39. The bounding temperature for the top and bottom DSC assemblies for the normal and accident case is 380°F and 610°F, respectively. All the welds are analyzed at the conservative temperature of 610°F for normal and accident load cases.

The weld stress design criteria and the allowable weld stress are given below.

Weld Stress Criteria (Reference 13.6)

Weld Stress Criteria Stress Item Service Levels Service Level Service Level D Service Level D Type A&B C (Elastic Analysis) (Plastic Analysis)

DSC Closure Primary 0.8 (1.5Sm) 0.8 (1.8Sm) 0.8 min(3.6Sm,Su) 0.8 (0.9Su)

Welds Secondary 0.8 (3.0Sm) N/A N/A N/A Primary 0.5 Sm 0.6 Sm min(1.2Sm,0.35Su) N/A Fillet Welds Secondary 0.75 Sm N/A N/A N/A Allowable Weld Stress (Reference 13.6)

Stress Values Stress Item Service Levels Service Level Service Level D Service Level D Type A&B C (Elastic Analysis) (Plastic Analysis)

DSC Closure Primary 19.68 23.62 47.23 45.65 Weld at Secondary 39.36 N/A N/A N/A 610°F Fillet Weld at Primary 8.20 9.84 19.68 N/A 610°F Secondary 12.30 N/A N/A N/A The NUHOMS-32PHB DSC is identical to NUHOMS-32P DSC, the only major difference being NUHOMS-32PHB basket has solid aluminum rails compared to stainless steel rails in the NUHOMS-32P basket. The other change is the lifting fixture of NUHOMS-32PHB which replaces the lifting blocks welded to inner bottom plate for NUHOMS-32P DSC with lifting lugs welded at the support ring at the top. These lifting lugs are evaluated in Reference 13.15. The lifting lug and associated welds are evaluated as an American Society for Mechanical Engineers (ASME) Code Subsection NF component using Level B stress allowables.

The NUHOMS-32PHB canister evaluation criteria are based on the rules of the ASME Code Section III. All components of the NUHOMS-32PHB DSC CALVERT CLIFFS ISFSI USAR 13.3-3 Rev. 26

are evaluated per Subsection NB of the Code. For welds of non-pressure-retaining parts, criteria are guided by the Code rules for component supports.

The component and weld qualification criteria are documented in Reference 13.2. The DSC welds are evaluated in Reference 13.6, Section 12 Appendix B.

Modified Transfer Cask Welds The transfer cask for the NUHOMS-32PHB is the same used for NUHOMS-32P DSC except the cask lid is modified for the NUHOMS-32PHB DSC transfer operation with forced cooling. The design modification consists of a new cask top lid with vent openings and added wedges between the bottom of canister and inner surface of the bottom cask to allow for forced convection cooling of cask interior.

The component interfaces in cask design include welded joints. Cask components and all its weld joints are under ASME Code NC-Subsection jurisdiction. Per ASME code requirement (Reference 13.38, NC-3355), the cask component dimensions and shape of the edges shall be such as to permit complete fusion and complete joint penetration of weld grooves. Per Reference 13.38, NC-4245, complete joint penetration is considered to be accomplished when the acceptance criteria for examination specified in Subsection NC have been achieved.

Full penetration groove welds are designed and fabricated to transfer all loads (including bending) of part they are connecting. That is, if the base metal at weld location is shown to be qualified - then these welds are also qualified. All locations of full penetration welds are addressed in the stress screening procedure described in Reference 13.14, Section 8. This calculation does not require a separate evaluation of full penetration welded joints.

American Society of Mechanical Engineers Code Subsection NC requires partial penetration welds localized in an area of low stress. Per Reference 13.2, for Service Level D conditions, weld qualification should to be addressed via elastic analysis methodology. Partial penetration welds are qualified via elastic analysis methodology in Reference 13.13.

The structural evaluation for the modified transfer cask is reconciled against the evaluation of transfer cask loaded with NUHOMS-32P in Reference 12.25 and described in Chapter 12. Component stresses are enveloped by those described in Chapter 12 with exception of some localized components which were shown to be acceptable in Reference 13.13.

13.3.3 SAFETY PROTECTION SYSTEMS 13.3.3.1 General USAR Section 3.3 discusses the CCNPP ISFSI design for the safe and secure long-term containment and storage of spent fuel. The NUHOMS-32PHB DSC is designed for storage of spent nuclear fuel as described in USAR Section 3.3.1 and in the following subsections.

CALVERT CLIFFS ISFSI USAR 13.3-4 Rev. 26

13.3.3.2 Protection by Multiple Confinement Barriers and Systems The NUHOMS-32PHB DSC provides confinement of the spent fuel similar to the NUHOMS-24P DSC and the NUHOMS-32P DSC. Sealing of the NUHOMS-32PHB DSC is leak tested in accordance with American National Standards Institute (ANSI) N14.5 after loading and sealing the canister, as described in USAR Section 3.3.2. Thus, the NUHOMS-32PHB DSCs are considered to be leak-tight per ANSI N14.5-1997.

Containment of radioactive material associated with spent fuel assemblies is provided by fuel cladding, the DSC stainless steel shell and double seal welded primary and secondary closures. There are no credible events that will breach a DSC to provide a possible leakage path to the environment (Reference 13.2, Section 10).

13.3.3.3 Protection by Equipment and Instrumentation Selection The protection by equipment and instrumentation is not impacted by the use of the NUHOMS-32PHB DSC, and remains the same as presented in Section 3.3.3.

The HSM-HBs are built with the ability to accommodate a temperature monitoring system whereas the current poured in place HSMs are not equipped with a temperature monitoring system. The temperature monitoring system is not-important-to-safety instrumentation and the loss of the system will not impact the safety function of the HSM-HBs to provide passive cooling to the DSCs. The air inlet and outlet vents of the HSM-HB are visually inspected every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for obstructions during any interruption of the operability of the HSM-HB temperature monitoring system.

13.3.3.4 Nuclear Criticality Safety The NUHOMS-32PHB DSC internals are designed to provide nuclear criticality safety during all phases of dry cask storage operations and storage, including wet loading operations and postulated accident conditions. The CCNPP site-specific NUHOMS-32PHB DSC design satisfies the requirements of Title 10 Code of Federal Regulations (CFR) 72.124 for normal, off-normal, and accident conditions.

13.3.3.4.1 Control Methods for Prevention of Criticality Criticality control is provided during the transfer cask fuel loading, DSC drying and sealing (wet conditions), and the transfer and storage phases (dry conditions). Control methods for the prevention of criticality under wet conditions consist of the physical properties of the fuel, fixed neutron absorbers in the NUHOMS-32PHB DSC basket, 2,450 ppm (Reference 13.33) soluble boron in the spent fuel pool water, and CCNPPs administrative controls for fuel identification, verification, and handling.

Rigorous measures are taken to exclude the possibility of introducing moderator into the DSC cavity during the dry CALVERT CLIFFS ISFSI USAR 13.3-5 Rev. 26

operations of transfer and storage. Prior to these operations, the DSC is vacuum dried, backfilled with helium, double seal welded, and helium leak tested to assure weld integrity.

Therefore, under normal operating conditions there is no possibility of a criticality incident. Since the transfer cask and the HSM-HB are designed to provide adequate drop and/or missile protection for the DSC, there is no credible accident scenario which would result in the possibility of the introduction of a moderator into the DSC; nor is there a credible accident scenario which would prohibit the canister from being opened and re-flooded.

13.3.3.4.2 Design Parameters for Criticality Model The design basis criticality analysis uses design parameters for Combustion Engineering, Inc. (CE) design 14x14 value added pellet (VAP) fuel assemblies and AREVA fuel lattices containing UO2 enriched up to 5.0 wt% U235 with geometry and fuel characteristics as shown in Table 6.2-1 (Reference 13.33, Section 6.1). The nominal dimensions of the NUHOMS-32PHB DSC are provided in USAR Table 13.3-1.

The geometry is illustrated in USAR Figure 13.3-1. A summary of the design parameters for the criticality analysis is presented in USAR Table 13.3-2.

13.3.3.4.3 Criticality Analysis Methods The CSAS5 control module of the SCALE 6 Program is used to calculate the effective multiplication factor (keff) of the fuel in the cask. The maximum keff for the calculation was determined with the following formula:

keff = kkeno + 2keno The CSAS5 control module allows simplified data input to the functional modules BONAMI, NITAWL, and KENO V.a. These modules process the required cross sections and calculate the keff of the system. BONAMI performs resonance self-shielding calculations for nuclides that have Bondarenko data associated with their cross-sections. NITAWLII applies a Nordheim resonance self-shielding correction to nuclides having resonance parameters. Finally, KENO V.a calculates the keff of a three-dimensional system. A sufficiently large number of neutron histories are run so that the standard deviation is below 0.0010 for all calculations. The criticality analysis used the 44-group cross-section library built into the SCALE 6 Program.

ORNL uses ENDF/B-V data to develop this broad-group library specifically for criticality analysis of a wide variety of thermal systems. The SCALE 6 computer code system was run with Widows-XP operating system.

A series of 102 benchmark criticality calculations are documented in Reference 13.34, Section 3.2. These calculations assume unirradiated fuel in the criticality analysis CALVERT CLIFFS ISFSI USAR 13.3-6 Rev. 26

and use the SCALE-6 computer code package. The upper subcriticality limit (USL), as described in NUREG/CR-6361, Section 4, is determined using the results of these 102 benchmark calculations (Reference 13.34, Section 3.2). The benchmark problems used to perform this verification are representative of benchmark arrays of commercial light water reactor fuels with the following characteristics:

• water moderation

• boron neutron absorbers

• unirradiated light water reactor type fuel (no fission products or "burnup credit")

• near room temperature (vs. reactor operating temperature)

• close reflection

• uranium oxide fuel The 102 uranium oxide experiments are chosen to model a wide range of uranium enrichments, fuel pin pitches, assembly separation, water/fuel ratio, concentration of soluble boron and control elements in order to test the codes ability to accurately calculate keff. The minimum value of the USL from Reference 13.34, Table 2 over the parameter range (in this case, the assembly separation distance) is 0.9410 (0.9410 is shown in Reference 13.33, Table 6.5-2 and Section 6.1). This USL value (0.9410) is based on a methodology bias and an administrative 5% margin on criticality. That is, keff < USL, ensures that keff is less than 0.95 (with 95% probability and 95%

confidence) when bias and uncertainty are taken into account.

For the criticality analyses, the criticality limits are shown in the following equation:

keff = (kkeno + 2keno) 0.9358 (Reference 13.33 Section 6.1) 13.3.3.4.4 Normal Conditions The calculated normal condition, "worst-case," reactivity (maximum keff) of a fully loaded NUHOMS-32PHB DSC is 0.9358 (Reference 13.33, Table 6.4-12). This is below the USL (0.9410), thus confirming that the "worst case" keff is 0.9410.

It conservatively includes allowances for uncertainties due to fuel positioning, basket rail modeling, compartment tube dimensions, poison plate thickness, and optimum moderator density. The "worst case" configuration includes the following:

• no credit for burnable absorbers in the fuel rods (e.g., erbia, etc.),

• fuel is unirradiated,

• the maximum uniform enrichment, 5.0 wt% U235, for all 32 fuel assemblies, CALVERT CLIFFS ISFSI USAR 13.3-7 Rev. 26

• an "inward" loading of all the 32 CE 14x14 fuel assemblies (i.e., all fuel assemblies are shifted toward the center of the DSC),

• credit for 90% of the of the absorber material (B10) in the fixed neutron absorbers in the NUHOMS-32PHB DSC basket assembly,

• a minimum compartment tube dimension of 8.47 inches,

• an internal moderator (soluble boron at 2,450 ppm Reference 13.33, Table 6.4-12) density of 0.75 (Reference 13.33, Table 6.4-11),

• an external (to the DSC and internal to the transfer cask) moderator (pure water) density of 100%

(Reference 13.33, Table 6.3-1).

13.3.3.4.5 Off-Normal Conditions Three postulated off-normal conditions are analyzed:

• Cask Drop Accidents,

• B10 Absorber Plates at Minimum Thickness, and

• Optimum Moderator Density.

These analyses confirm that the off-normal conditions will not result in a DSC storage array with a reactivity higher than the USL of 0.9410 (Reference 13.33 Section 6.4.1).

Cask Drop Accidents The criticality analysis for the cask drop accidents demonstrates that the most reactive configuration is the triple contingency accident involving fuel damage, optimum pitch (due to grid deformation), and optimum moderator density. For the helium-moderated system, the keff is 0.9358 which is below the USL (0.9410). For the borated water moderated system, the maximum keff is 0.9358, which is also below the USL (0.9410).

B10 Poison Plate Thickness Variation The criticality analysis for sensitivity to B10 absorber plate thickness demonstrates that there is enough conservatism in the plate loading of 24.3 mg B10/cm2 to offset changes in reactivity due to a reduction in thickness. Credit is taken for 90% of the B10 loading in the analysis. For the "worst case,"

with a B10 loading of 24.3 mg/cm2, a thickness of 0.0791 inches, and optimum moderator density, the keff, is calculated to be 0.9358 (Reference 13.33, Table 6.4-12).

Updated Safety Analysis Report Section 13.3.3.4.7 has a detailed discussion on poison plate acceptance testing.

CALVERT CLIFFS ISFSI USAR 13.3-8 Rev. 26

Optimum Moderation Since all reported reactivities include an allowance for optimum moderator density, and all reported reactivities are less than the USL, a criticality event due to moderator density alone is not credible. Therefore subcriticality is assured, even in the event that a flooded DSC remains out of the pool long enough for boiling to occur.

13.3.3.4.6 Criticality Analysis Method Verification The analysis method which ensures a subcriticality margin of greater than 5% under all normal conditions uses the CSAS5, of the SCALE-6 package of codes, the v5-44 cross-section library and the NITWAL option are used. (Reference 13.33, Section 6.4.1, Reference 13.34, Section 3.0).

A series of 102 benchmark criticality calculations are documented in Reference 13.34. These calculations assume unirradiated fuel in the criticality analysis and use the SCALE-6 computer code package to demonstrate its applicability and to establish methods bias and variability.

13.3.3.4.7 B10 Poison Plate Testing Description The poison plates consist of wrought aluminum containing boron, which is isotopically enriched to approximately 95 wt%

B10. Because of the negligibly low solubility of boron in solid aluminum, the boron appears entirely as discrete second phase particles of AlB2 in the aluminum matrix. The effect on the properties of the matrix aluminum alloy are those typically associated with a uniform fine (1-10 micron) dispersion of an inert equiaxed second phase.

The nominal plate thickness is 0.125 inches.

The design minimum B10 areal density is 24.3 mg B10/cm2 (Reference 13.33, Table 6.4-12).

Functional Requirements of Poison Plates The poison plates serve as a neutron absorber for criticality control and as a heat conduction path. The NUHOMS-32PHB DSC safety analysis does not rely upon their mechanical strength. The radiation and temperature environment in the DSC is not severe enough to damage the aluminum matrix that retains the boron-containing particles. To assure performance of the plates important-to-safety functions, the critical variables that need to be verified are thermal conductivity and B10 areal density.

CALVERT CLIFFS ISFSI USAR 13.3-9 Rev. 26

Borated Aluminum Test Coupon and Lot Definitions Test coupons will be taken so that there is at least one coupon contiguous with each plate. These coupons will be used for neutron transmission and thermal conductivity testing.

A lot is defined as all the plates produced from a single cast ingot, or all the plates produced from a single heat.

Thermal Conductivity Testing of Poison Plates The poison plate material is qualification-tested to verify that the thermal conductivity equals or exceeds the design requirements.

Testing may be by American Society for Testing and Materials (ASTM) E1225, ASTM E1461, or equivalent method.

B10 Areal Density Testing of Poison Plates The testing program for the NUHOMS-32PHB DSC poison plates meet the requirements of NUREG/CR-5661.

The effective B10 content is verified by neutron transmission testing of the coupons. The transmission through the coupons is compared with transmission through calibrated standards.

The neutron transmission testing measurements are taken using a collimated neutron beam. The neutron transmission test procedure includes provisions to vary the selected measurement location along the coupon length.

The acceptance criterion for neutron transmission testing is that the B10 areal density, minus 3 based on the number of neutrons counted for that measurement, must be greater than or equal to the minimum value 24.3 mg B10/cm2.

Macroscopic uniformity of B10 distribution is verified by neutron radioscopy/radiography of the coupons. The acceptance criterion is that there is uniform luminance across the coupon.

This inspection shall cover the entire coupon. If a coupon fails this test, the associated plate is rejected.

In addition, a statistical analysis of the neutron transmission results for all plates in a lot is performed. This analysis shall demonstrate, using a one-sided tolerance limit factor for a normal distribution with at least 95% probability, the areal density is greater than or equal to the specified minimum value of 24.3 mg B10/cm2 with 95% confidence level.

13.3.3.5 Radiological Protection The discussion presented in USAR Section 3.3.5 is not affected by the addition of the NUHOMS-32PHB DSC and the HSM-HB to the NUHOMS system. However, the maximum contact dose on the exterior surface of the CALVERT CLIFFS ISFSI USAR 13.3-10 Rev. 26

transfer cask containing a fuel-loaded NUHOMS-32PHB DSC has been increased to 250 mrem/hr from 200 mrem/hr for a transfer cask loaded with a fuel-loaded NUHOMS-24P or NUHOMS-32P DSC. See USAR Section 13.7 for additional discussion on radiation protection design considerations for the NUHOMS-32PHB DSC and the HSM-HB.

13.3.3.6 Fire and Explosions Protection The discussion presented in USAR Section 3.3.6 is applicable to the NUHOMS-32PHB DSC and the HSM-HB. The effects of a forest fire around the facility are discussed in USAR Section 13.8.2.10.

13.3.3.7 Materials Handling and Storage The evaluation presented in USAR Section 3.3.7 is applicable to the NUHOMS-32PHB DSC and the HSM-HB, with the exception of peak cladding temperatures which are higher than those of the NUHOMS-32P DSC. For long-term storage, the HSM-HB passive ventilation maintains the maximum normal operating fuel clad temperature at 724°F or less (assuming a 104°F ambient temperature) as documented in Reference 13.23, Table 6-1. During short-term conditions, such as DSC draining and drying, transfer of the DSC to/from the HSM-HB, the maximum fuel cladding temperature is 728°F as documented in References 13.23 and 13.28, which remains below the limit of 752°F. For off-normal and accident temperature conditions (Reference 13.23), the fuel cladding temperature maximum value is 932°F (Reference 13.23, Table 6-1 only for an accident with high burnup),

which is significantly less than the maximum allowable value of 1,058°F.

As documented in Reference 13.28, Section 4.1, backfilling the DSC with helium gas causes a one time temperature drop, which is not considered as a repeated thermal cycling. Re-evacuation of the DSC under a helium atmosphere does not reduce the pressure sufficiently to decrease the thermal conductivity of helium. Therefore, re-evacuation and re-pressurizing the DSC under a helium atmosphere proceeds on a descending curve to the minimum steady state temperatures, and does not include any thermal cycling. It is concluded that the limit of 65°C (117°F) considered for thermal cycling during loading operations is satisfied for the NUHOMS-32PHB DSC system.

13.3.3.8 Industrial and Chemical Safety The discussion presented in USAR Section 3.3.8 is applicable to the NUHOMS-32PHB DSC and the HSM-HB.

13.3.4 CLASSIFICATION OF STRUCTURES, COMPONENTS, AND SYSTEMS The discussion presented in USAR Section 3.4 is applicable to the NUHOMS-32PHB DSC and the HSM-HB.

13.3.5 DECOMMISSIONING CONSIDERATIONS The discussion presented in USAR Section 3.5 is applicable to the NUHOMS-32PHB DSC and the HSM-HB.

CALVERT CLIFFS ISFSI USAR 13.3-11 Rev. 26

13.3.6

SUMMARY

OF DESIGN CRITERIA USAR Tables 13.3-3 to 13.3-5 provide a summary of the design criteria information for the normal, off-normal, and accident conditions, respectively for the HSM-HB, NUHOMS-32PHB DSC and the transfer cask.

CALVERT CLIFFS ISFSI USAR 13.3-12 Rev. 26

TABLE 13.3-1 NUHOMS-32PHB DRY SHIELDED CANISTER DIMENSIONS GEOMETRY DESCRIPTION NOMINAL DIMENSIONS (inches)

Guide Sleeve Inside Dimension7 8.50 Guide Sleeve Thickness7 0.1874 Center to Center Spacing8 9.125 Stainless Steel Strip Thickness8 0.25 Aluminum + Poison Plate Thickness7 0.245 Basket Assembly Length6 158.0 max.

DSC Shell Outside Diameter2 67.25 DSC Shell Inside Diameter6 66.0 DSC Shell Length (with grapple ring)1,9 176.50 DSC Shell Thickness2,6 0.625 Top Shield Plug Thickness4 6.25 Top Cover Plate Thickness5 1.25 DSC Lead Shielding Thickness

• Top Shield Plug4 4.0 min.

• Bottom Shield Plug1 4.25 min.

Vent / Siphon Port Tube Inside Diameter3 1.05

References:

1. 13.48

2. 13.49

3. 13.50

4. 13.51

5. 13.52

6. 13.53

7. 13.54

8. 13.55

9. 13.31 Section 5.0 CALVERT CLIFFS ISFSI USAR 13.3-13 Rev. 26

TABLE 13.3-2 DESIGN PARAMETERS FOR CRITICALITY ANALYSIS OF THE NUHOMS-32PHB DSC PARAMETERS DESIGN VALUE FUEL ASSEMBLIES Number/Type 32/CE design 14x14, VAP and AREVA Rod Array 14x14 Number of Fuel Rods 176 Number of Control Rod Guide Tubes 5 Number of Instrument Tubes 1 (1 of the 5 guide tubes)

Rod Pitch (inches) 0.580 Burnup Credit Not Applicable for the NUHOMS-32PHB DSC FISSILE CONTENT wt% U235 (Standard) CE 4.5 max.

wt% U235 (VAP) 5.0 max.

wt% U235 (AREVA) 5.0 max.

FUEL PELLETS Density (Standard, Theoretical) CE 96.0% max Density (VAP, Theoretical) 96.0% max Density (AREVA, Theoretical) 96.0% max Diameter (inches, Standard) CE 0.3765(a)

Diameter (inches, VAP) 0.3810 Diameter (inches, AREVA) 0.3805 FUEL ROD CLADDING Material AREVA (M5)

Standard (CE) and VAP (Zircaloy-4)

Thickness (inches, Standard) CE 0.028(a)

Thickness (inches, VAP) 0.026 Thickness (inches, AREVA) 0.0315 Outside Diameter (inches, Standard) CE 0.440 Outside Diameter (inches, VAP) 0.440 Outside Diameter (inches, AREVA) 0.440 CONTROL ROD GUIDE TUBES Material Zircaloy-4 Thickness (inches) 0.040 Outside Diameter (inches) 1.115 INSTRUMENT TUBE Material Zircaloy-4 Thickness (inches) 0.040 Outside Diameter (inches) 1.115 DSC COMPARTMENTS Material Stainless Steel Thickness (inches) 0.1874 Inside Diameter (inches) 8.5 DSC POISON PLATES Number 150 Material B4C MMC Density (g/cm3) 2.52 CALVERT CLIFFS ISFSI USAR 13.3-14 Rev. 26

TABLE 13.3-2 DESIGN PARAMETERS FOR CRITICALITY ANALYSIS OF THE NUHOMS-32PHB DSC PARAMETERS DESIGN VALUE Thickness (inches) 0.125 (0.120)(c)

B10 Areal density (mg/cm2) Basket A > 17.1(d)

Basket B > 24.3(d)

Location See USAR Figure 13.3-1 DSC FILL MATERIAL Material (wet) Borated Water (2,450 ppm min.)

Moderator Density (wet) 0.01% to 100%

Material (dry) helium Moderator Density (dry) 1.785E-04 g/cm3/atm DSC SHELL Material Stainless Steel Thickness (inches) 0.625 Outside Diameter (inches) 67.25 CASK Material Stainless Steel/Lead Thickness (inches) 6.25(b)

Outside Diameter (inches) 80.5(b)

(a) The fuel pellet outside diameter and clad thickness varied slightly for Fuel Batches A, B, and C in Units 1 and 2. These variances do not affect the results of the design basis analysis.

(b) Exclusive of the cask neutron shield.

(c) Reference 13.55 Note 8 (d) Reference 13.33 CALVERT CLIFFS ISFSI USAR 13.3-15 Rev. 26

TABLE 13.3-3 NUHOMS-32PHB DSC

SUMMARY

OF DESIGN CRITERIA FOR NORMAL OPERATING CONDITIONS DESIGN APPLICABLE COMPONENT LOAD TYPE SOURCE DESIGN PARAMETERS CODE HSM-HB Dead Load Ref 13.10 Dead weight including loaded DSC ANSI 57.9-1984 Ref 13.2 ACI 349-97 and ACI 349R-97 Load Combination USAR Table 3.2-2 Load combination methodology ANSI 57.9-1984 Sec 6.17.1.1 Design Basis Ref 13.23, Table DSC with spent fuel rejecting 29.6 kW decay ANSI 57.9-1984 Operating 4-9 Note 3 heat. Ambient air temperature range -8°F to Temperature Ref 13.44 104°F Normal Handling Ref 13.2, Table Hydraulic ram load: 23,750 lb ASCE 7-95 Loads 8-11 Design Load: 80,000 lb (Insertion) 60,000 lb (retrieval)

Snow and Ice Loads USAR Section Design load: 110 psf (included in live load) ASCE 7-95 3.2.4 Live Loads Ref 13.10 Design load: 200 psf ANSI 57.9-1984 Shielding USAR Section Contact dose rate on HSM-HB exterior ANSI 57.9-1984 4.2.3.1 surface 20 mrem/hr. HSM-HB door 100 Ref 13.31 mrem/hr DSC Dead Loads Ref 13.3 Weight of loaded DSC: 92,402 lb nominal, ANSI 57.9-1992 95,000 lb enveloping Design Basis Internal Ref 13.24 DSC internal pressure 15.0 psig ANSI 57.9-1992 Pressure Load Structural Design Ref 13.6 Service Level A and B ASME B&PV Code Sec III, Div 1, NB, Class 1(1)

Design Basis Ref 13.23, Table DSC decay heat 29.6 kW. Ambient air ANSI 57.9-1992 Operating 4-9 Note 3 temperature -8°F to 104°F Temperature Loads Operational Handling Ref 13.2, Table Hydraulic ram load: 23,750 lb ANSI 57.9-1992 8-11 Design Load: 60,000 lb Criticality USAR Section Keff less than 0.95 ANSI 57.9-1992 13.3.3.4 CALVERT CLIFFS ISFSI USAR 13.3-16 Rev. 26

TABLE 13.3-3 NUHOMS-32PHB DSC

SUMMARY

OF DESIGN CRITERIA FOR NORMAL OPERATING CONDITIONS DESIGN APPLICABLE COMPONENT LOAD TYPE SOURCE DESIGN PARAMETERS CODE DSC Support Dead Loads Ref 13.2 Loaded DSC + self weight: 95,000 lb ANSI 57.9-1992 Assembly AISC Code 9th Edition Operational Handling USAR Section DSC reaction load with hydraulic ram load: ANSI 57.9-1992 13.8.1 23,750 lb Ref 13.10 Transfer Cask Normal Operating Ref 13.2 Service Level A and B ASME B&PV Code Condition Sec III, Div 1, Class 2, NC-3200(1)

Transfer Cask Dead Loads Ref 13.13 a) Vertical orientation, self weight + loaded ANSI 57.9-1984 Shell, Rings, etc. Ref 13.11 DSC + water in cavity: 220,000 lb enveloping b) Horizontal orientation, self weight + ANSI 57.9-1984 loaded DSC on transfer skid:

215,000 lb enveloping Snow and Ice Loads USAR Section External surface temperature of cask will 10 CFR 72.122 3.2.4 preclude buildup of snow and ice loads when in use: 110 psf Design Basis Ref 13.23, Table Loaded DSC rejecting 29.6 kW decay heat. ANSI 57.9-1984 Operating 4-9 Note 3 Ambient air temperature range -8F to 104F Temperature Loads Ref 13.26 (Forced-cooling Ref 13.21 Minimum airflow rate 450 cfm for heat load Configuration) > 21.12 kW Shielding USAR Section Contact dose rate 250 mrem/hr ANSI 57.9-1984 13.7.1.2 Ref 13.2 Transfer Cask Operational Handling Ref 13.2, Table a) Upper lifting trunnions while in Auxiliary ANSI N14.6-1978 Upper Trunnions 9-10 Building:

Ref. 13.8 i) Stress must be less than yield stress for 6 times critical load of 126,500 lb/

trunnion nominal CALVERT CLIFFS ISFSI USAR 13.3-17 Rev. 27

TABLE 13.3-3 NUHOMS-32PHB DSC

SUMMARY

OF DESIGN CRITERIA FOR NORMAL OPERATING CONDITIONS DESIGN APPLICABLE COMPONENT LOAD TYPE SOURCE DESIGN PARAMETERS CODE Ref 13.2 ii) Stress must be less than ultimate stress for 10 times critical load USAR Table 3.2-4 b) Upper lifting trunnions for on-site transfer: ASME B&PV Code i) Dead Load +/- 1g vertically Sec III, Div 1, Class 2, ii) Dead Load +/- 1g axially NC-3200(1) iii) Dead Load +/- 1g laterally iv) Dead Load (+/- 1/2g vertically +/- 1/2g axially + 1/2g laterally)

Transfer Cask Operational Handling Ref 13.3 Lower support trunnions weight of loaded ASME B&PV Code Lower Trunnions cask during downloading and transit to HSM- Sec III, Div 1, Class 2, HB NC-3200(1)

Transfer Cask Operational Handling Ref 13.2 Hydraulic ram load due to friction of extracting ANSI 57.9-1984 Shell loaded DSC: 60,000 lb Transfer Cask Normal Operation Ref 13.2, Table Service levels A, B, C and D ASME B&PV Code Bolts 9-11 Avg stress less than 2 Sm for A,B,C Section III, Div 1, Max stress less than 3 Sm for A,B,C Class 2, NC-3200(1)

ACI American Concrete Institute AISC American Institute of Steel Construction B&PV Boiler and Pressure Vessel (1) ASME B&PV Code-1983, with Addenda up to 1985 for HSM-HB and Transfer Cask ASME B&PV Code-1998, with Addenda up to 1999 for DSC CALVERT CLIFFS ISFSI USAR 13.3-18 Rev. 26

TABLE 13.3-4 NUHOMS-32PHB DSC

SUMMARY

OF DESIGN PARAMETERS FOR OFF-NORMAL OPERATING CONDITIONS DESIGN APPLICABLE COMPONENT LOAD TYPE SOURCE DESIGN PARAMETERS CODE HSM-HB Off-Normal Temperature Ref 13.2, Table 8-10 -8°F and 104°F ambient temperature ANSI 57.9-1984 Jammed Condition Ref 13.2, Table 8-11 Hydraulic ram load equal to 80,000 lb ANSI 57.9-1984 Handling Ref 13.10, Table 7-2 Design Load: 80,000 lb (insertion) 80,000 lb (retrieval)

Load Combination USAR Table 8-11 Load combination methodology ANSI 57.9-1984 Ref 13.10, Table 7-2 Sec 6.17.1.1 DSC Off-normal Temperature Ref 13.2, Table 8-10 -8°F and 104°F ambient temperature ANSI 57.9-1992 Off-normal Pressure Ref 13.2, Table 8-9 DSC internal pressure: 20 psig ANSI 57.9-1992 Blowdown Pressure Ref 13.2, Table 8-9 DSC internal pressure: 20 psig 10 CFR 72.122(b)

Ref 13.18, Section 5.1 Jammed Condition Ref 13.2, Table 8-11 Hydraulic ram load equal to 80,000 lb ANSI 57.9-1992 Handling Ref 13.6, Table 4-3 Design Load: 95,000 lb Structural Design Off- Ref 13.2 Service Level C ASME B&PV Code Normal Conditions Sec III, Div 1, NB, Class 1 DSC Support Jammed Handling USAR Section Hydraulic ram load: 95,000 lb ANSI 57.9-1992 Condition 13.8.1.2.1 Load Combination Ref 13.6, Table 5-1 Load combination methodology ANSI 57.9-1992 Transfer Cask Off-normal Temperature -8°F and 104°F ambient temperature ANSI 57.9-1992 Jammed Condition Ref 13.2, Table 8-11 Hydraulic ram load: 80,000 lb ANSI 57.9-1992 Handling Ref 13.10, Table 7-2 Structural Design Off- Ref 13.2, Table 9-10 Service Level C ASME B&PV Code Normal Conditions Sec III, Div 1, Class 2, NC-3200 Bolts, Off-Normal Ref 13.2, Table 9-11 Service Level C ASME B&PV Code Conditions Avg stress less than 2 Sm Sec III, Div 1 Class 2, Max stress less than 3 Sm NC-3200 CALVERT CLIFFS ISFSI USAR 13.3-19 Rev. 26

TABLE 13.3-5 NUHOMS-32PHB DSC

SUMMARY

OF DESIGN CRITERIA FOR ACCIDENT CONDITIONS DESIGN APPLICABLE COMPONENT LOAD TYPE SOURCE DESIGN PARAMETERS CODE HSM-HB Design Basis USAR Section 3.2.1 Max velocity 360 mph RG 1.76 Tornado Ref 13.10, Section 7 Max wind pressure 344 psf ANSI 58.1 1982 Load Combination USAR Table 3.2-2 Load Combination Methodology ANSI 57.9-1984 Sec 6.17.1.1 Design Basis Ref 13.10, Table Types: NUREG-0800 Tornado Missiles 10-1 Automobile, 4,000 lb, 195 fps Sec 3.5.1.4 USAR Section 8" diam artillery shell, 276 lb, 185 fps 13.3.2.1 12" steel pipe, 1500 lb, 205 fps 6 steel pipe, 285 lbs, 230 fps Wood plank, 200 lbs, 440 fps (300 mph) 3 steel pipe, 115 lbs, 268 fps 1 steel rod, 8 lbs, 317 fps Flood USAR Section Dry Site 13.3.2.2 Seismic USAR Section Horizontal ground acceleration 0.30g NRC RGs 1.60 and 13.3.2.3 Vertical ground acceleration 0.20g 1.61 Ref 13.2 7% critical damping Accident Condition USAR Section HSM-HB vents (inlet/outlet) blocked for ANSI 57.9-1984 Temperature 13.8.2.7 36 hrs or less. HSM-HB inside surface Ref 13.10, Figure temperature: 408°F 7-3 Fire Ref 13.40, Table 4-1 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> forest fire 130 feet from HSM-HB ISG-11 Rev. 3 Explosions USAR Section Probability of liquefied natural gas spill NUREG-0800 8.2.11 affecting HSM-HB < 10-7 Section 2.2.3 DSC Accident Drop USAR Section Equivalent static deceleration: RG 1.61 13.8.2.5 75g vertical end drop ACI 349R-97 Ref 13.2 75g horizontal side drop 25g corner drop with slap down (corresponds to an 80 inch drop height)

Structural damping during drop: 10%

Flood Ref 13.10, Table 7-2 Maximum water height: 50 feet 10 CFR 72.122(b)

CALVERT CLIFFS ISFSI USAR 13.3-20 Rev. 26

TABLE 13.3-5 NUHOMS-32PHB DSC

SUMMARY

OF DESIGN CRITERIA FOR ACCIDENT CONDITIONS DESIGN APPLICABLE COMPONENT LOAD TYPE SOURCE DESIGN PARAMETERS CODE Seismic USAR Section Horizontal acceleration: 0.41g NRC RGs 1.60 and 13.8.2.3.2 Axial acceleration: 0.36g 1.61 Ref 13.2 Vertical acceleration: 1.25g 3% critical damping Accident Internal USAR Section DSC internal pressure: 100 psig based on 10 CFR 72.122(b)

Pressure (HSM-HB 13.8.2.7 100% fuel clad rupture and fill gas release, vents blocked) Ref 13.6, Table 4-3 and ambient air temp. = 104°F.

DSC shell temperature: 595°F Blocked vent time = 36 hrs Accident Conditions Ref 13.2, Section 8 Service Level D ASME B&PV Code Sec III, Div 1, NB, Class 1 Maximum Pressure Ref 13.24, Table 7-1 DSC internal pressure: 91.4 psig 10 CFR 72.122(i) during Transfer and USAR Section Storage 13.8.2.9.2 DSC Support Seismic USAR Section DSC reaction loads: NRC RGs 1.60 and Assembly 13.8.2.3.2 Horizontal acceleration: 0.43g 1.61 Ref 13.10, Section Vertical acceleration: 0.20g 5.9 7% critical damping Load Combination USAR Table 13.8-4 Load combination methodology ANSI 57.9-1984 Sec 6.17.3.2.1 Transfer Cask Design Basis Ref 13.45, Section Max wind velocity: 360 mph NRC RG 1.76, Tornado 3.2.1 Max wind pressure: 397 psf ANSI 58.1-1982 Design Basis Ref 13.45, Section Automobile, 3967 lb NUREG-0800 Tornado Missiles 3.2.1 8 diameter artillery shell, 276 lb Sec 3.5.1.4 Flood Ref 13.45, Section Cask use to be restricted by administrative 10 CFR 72.122 3.2.2 controls Seismic Ref 13.45, Section Horizontal ground acceleration: 0.25g NRC RGs 1.60 and 3.2.3 (both directions) 1.61 Vertical acceleration: 0.17g 3% critical damping CALVERT CLIFFS ISFSI USAR 13.3-21 Rev. 26

TABLE 13.3-5 NUHOMS-32PHB DSC

SUMMARY

OF DESIGN CRITERIA FOR ACCIDENT CONDITIONS DESIGN APPLICABLE COMPONENT LOAD TYPE SOURCE DESIGN PARAMETERS CODE Accident Drop Ref 13.45, Section Equivalent static deceleration: 10 CFR 72.122(b) 8.2.5 75g vertical end drop 75g horizontal side drop 25g corner drop with slapdown (corresponds to an 80 inch drop height)

Structural damping during drop 10% RG 1.61 Bolts, Accident Drop Ref 13.45, Table Service Level D ASME B&PV Code 3.2-9 Sec III, Div 1, Class 2, NC-3200 Structural Design, Ref 13.45, Table Service Level D ASME B&PV Code Accident 3.2-8 Sec III, Div 1, Class 2, NC-3200 Internal Pressure -- Not applicable because DSC provides 10 CFR 72.122(b) pressure boundary CALVERT CLIFFS ISFSI USAR 13.3-22 Rev. 26

TABLE 13.3-6 NUHOMS-32PHB DSC DESIGN LOAD COMBINATIONS (Reference 13.2)

Emergency Conditions / Accident Normal Operating Conditions Off-Normal Conditions Load Combination Case Conditions 1 2 3 4 5 6 7 1 2 3 4 5 6 1 2 3 4 5 6 7 Vertical, DSC Empty X Dead Weight Vertical, DSC w/ and w/o Water X Horizontal, DSC w/Fuel X X X X X X X X X X X X X X X X X X Inside HSM: 70°F (ambient) X X Inside Cask: 70°F (ambient) X X X X X X X Inside HSM: 104°F (ambient) X X X Thermal Inside Cask: 104°F (ambient) X X X Inside Cask: Accident X X Inside HSM: Accident (vent block) X Normal Pressure X X X X X Internal Pressure Off-Normal / Blowdown X X X X X X X Accident X X External Pressure Hydrostatic X Normal X X Handling Loads Off-Normal X X X Normal X X X X Transfer Loads Accident (Drop) X X Seismic X ASME Code Service Level A A A A A A A B B B B B B C C D D D D D CALVERT CLIFFS ISFSI USAR 13.3-23 Rev. 26

13.4 INSTALLATION DESIGN The discussion presented in Chapter 4 is applicable to the NUHOMS-32PHB DSC and the HSM-HB. Chapter 4 describes the installation design associated with the CCNPP ISFSI and related systems. The narrative describes the installation design unique to the CCNPP ISFSI systems, such as the storage structures, auxiliary systems, decontamination systems, transfer cask repair and maintenance, and the fuel handling operation systems. The CCNPP ISFSI is a self-contained, passive storage facility, which requires no auxiliary systems.

CALVERT CLIFFS ISFSI USAR 13.4-1 Rev. 26

13.5 OPERATION SYSTEMS The discussion presented in Chapter 5 is applicable to the CCNPP ISFSI facility addition of the NUHOMS-32PHB DSC, the HSM-HBs, the self-propelled modular transporter, the hydraulic ram, and transfer cask support skid used with the self-propelled modular transporter and the transfer cask in the forced-cooling configuration. Chapter 5 describes the operation of the CCNPP ISFSI.

The narrative describes operations unique to the CCNPP ISFSI systems, such as draining, drying, and closure of the DSC and the use of the self-propelled modular transporter. Although some operational details are provided, the description is not intended to limit or restrict operation of the facility. Operational procedures may be revised according to the requirements of the plant, provided that the limiting conditions of operation are not exceeded.

CALVERT CLIFFS ISFSI USAR 13.5-1 Rev. 26

13.6 SITE GENERATED WASTE CONFINEMENT AND MANAGEMENT The discussion presented in Chapter 6 is applicable to the CCNPP ISFSI facility addition of the NUHOMS-32PHB DSC, the HSM-HBs, the self-propelled modular transporter, the hydraulic ram, and transfer cask support skid used with the self-propelled modular transporter and the transfer cask in the forced-cooling configuration. Chapter 6 describes the on-site waste sources, off-gas treatment and ventilation, liquid waste treatment and retention, solid wastes and radiological impact of normal operations of the CCNPP ISFSI.

CALVERT CLIFFS ISFSI USAR 13.6-1 Rev. 26

13.7 RADIATION PROTECTION This section contains the radiation protection discussion as it relates to the NUHOMS-32PHB DSC and the HSM-HB. The outline and content of this section is based on Chapter 7. The NUHOMS-32PHB DSC and the HSM-HB provides enhanced shielding which helps to compensate for the higher source term of spent fuel elements compared to the NUHOMS-24P and NUHOMS-32P DSCs. Dose rates for the NUHOMS-32PHB DSC within the HSM-HB and the transfer cask are presented in Table 13.7-1. The CCNPP site-specific ISFSI facility design meets the requirements of 10 CFR 72.104 and 10 CFR 72.106 for normal, off-normal, and accident conditions (References 13.30, 13.31, and 13.32).

The principal system, subsystem and components of the CCNPP ISFSI for a NUHOMS-32PHB DSC are listed in USAR Table 1.3-2. Updated Safety Analysis Report Tables 1.2-3, 13.3-1, and 13.3-2 lists the capacity, dimensions, and design parameters for the NUHOMS-32PHB DSC.

The differences between the NUHOMS-32PHB DSC and the NUHOMS-32P DSC that affect shielding and radiation protection are:

• increasing the maximum fuel assembly neutron source term from 4.175E+08 n/sec/assy to 6.664E+08 n/sec/assy (Reference 13.2 Table 4-2),

• increasing the maximum fuel assembly gamma source term from 1.61E+15 MeV/sec/assy to 2.56E+15 MeV/sec/assy,

• full-length solid aluminum rail inserts between the DSC stainless steel cylindrical shell and the outside guide sleeves, and

• a redesign of the top shield plug (including vent and siphon ports).

The differences between the HSM-HB and the HSM that affect shielding and radiation protection are:

• Use of a 3-foot 8-inch thick roof and walls on HSM-HB versus 3-foot thick roof and walls on the HSM,

• HSM-HB door is inset in the doorway, with increased thickness,

• Outlet vents repositioned from top front and back of module to top sides (opening shared by adjacent modules),

• Inlet vents repositioned from front bottom center to front bottom sides (opening shared by adjacent modules), and

• Optional inlet vent attenuation pipes improves shielding (pipes are not credited for normal, off-normal or accident conditions).

The radiation protection and shielding aspects of the NUHOMS-32PHB DSC and the HSM-HB, and the effects of these differences, are addressed in detail below.

13.7.1 ENSURING THAT THE OCCUPATIONAL RADIATION EXPOSURES ARE AS LOW AS REASONABLY ACHIEVABLE 13.7.1.1 Policy Considerations The discussion in USAR Section 7.1.1 is applicable to NUHOMS-32PHB DSC and the HSM-HB.

13.7.1.2 Design Considerations - NUHOMS-32PHB DSC Like the NUHOMS-32P DSC discussed in USAR Section 12.7, the NUHOMS-32PHB DSC can store 32 spent fuel assemblies (all CE 14x14 CALVERT CLIFFS ISFSI USAR 13.7-1 Rev. 26

fuel of the Standard, Westinghouse VAP, and AREVA designs used at CCNPP have been considered). The maximum heat source of the spent fuel assemblies for the NUHOMS-32PHB DSC is increased to 1.0 kW (maximum of 29.6 kW per canister when zone loaded with 0.8 kW fuel assemblies), compared to 0.66 kW per fuel assembly for the NUHOMS-24P DSC and the NUHOMS-32P DSC. This means that the fuel assemblies for the NUHOMS-32PHB DSC may spend less time cooling in the spent fuel pool before being transported to the ISFSI. Thus, the maximum radiation source in the NUHOMS-32PHB DSC may be at a higher level than the NUHOMS-24P or NUHOMS-32P DSCs. The design considerations which ensure that occupational exposures for the CCNPP ISFSI utilizing the NUHOMS-24P DSC and the original poured in place HSMs are as low as reasonably achievable are discussed in USAR Section 7.1.2. The following paragraphs, which are numbered to correspond with USAR Section 7.1.2, discuss differences in the NUHOMS-24P and/or NUHOMS-32P DSCs, and the NUHOMS-32PHB DSC designs, which affect the shielding design considerations.

1-3. These items are the same as in USAR Section 7.1.2.

4. The contact dose goal for a transfer cask with a NUHOMS-32PHB DSC is 250 mrem/hr or less (Reference 13.2).

5-7. These items are the same as in USAR Section 7.1.2.

8. USAR Section 7.1.2 states that the cavity of the NUHOMS-24P DSC will be submerged in the spent fuel pool for about 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and, on removal from the pool, will contain borated water from the spent fuel pool for less than 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br />. Because of the larger number of fuel assemblies (32 opposed to 24) to be stored in the NUHOMS-32PHB DSC, it is expected that the DSC will be submerged in the pool for a longer period of time than the NUHOMS-24P DSC, but similar to the NUHOMS-32P DSC. This additional submersion time does not affect the performance of the austenitic stainless steel as discussed in USAR Section 7.1.2. The NUHOMS-32PHB DSC also contains aluminum plates (borated and un-borated). There is a substantial body of industry experience with exposure of aluminum to borated and unborated water and its performance is not affected by the pool conditions. Due to the use of solid aluminum rails at the basket periphery, the surface area of exposed metal is less than in the NUHOMS-32P DSC.

9-13. These items are the same as in USAR Section 7.1.2.

14. The discussion in USAR Section 7.1.2 is unchanged, with the exception that the NUHOMS-32PHB DSC is loaded into the transfer cask modified for forced-cooling configuration.

15. This item is the same as in USAR Section 7.1.2.

CALVERT CLIFFS ISFSI USAR 13.7-2 Rev. 26

13.7.1.3 Operational Considerations The discussion in USAR Section 7.1.3 is applicable to the NUHOMS-32PHB DSC and the HSM-HB.

13.7.2 RADIATION SOURCES - NUHOMS-32PHB 13.7.2.1 Characterization of Sources The radiological source terms were calculated using SAS2H/ORIGEN-S codes of the SCALE package for the range of initial enrichments and burnups given in Table 9.4-4. The source terms were calculated with cooling times for each fuel assembly corresponding to maximum heat output of 0.8 kW and 1.0 kW.

The fuel assembly with the largest gamma source terms at a heat load of 1.0 kW for both the HSM-HB and the transfer cask in the forced-cooling configuration was found to be VAP fuel with 4.25 wt% initial enrichment, 42,000 MWD/MTU burnup, cooled for 4.2 years.

The fuel assembly with the largest gamma source terms at a heat load of 0.8 kW for both the HSM-HB and the transfer cask in the forced-cooling configuration was found to be VAP fuel with 4.27 wt% initial enrichment, 36,000 MWD/MTU burnup, cooled for 4.4 years.

The fuel assembly with the largest neutron source terms for both the HSM-HB and the transfer cask in the forced-cooling configuration was found to be AREVA fuel with 4.0 wt% initial enrichment, 58,000 MWD/MTU burnup, cooled for 9.4 years to reach 1.0 kW and 16.4 years to reach 0.8 kW.

The neutron and gamma energy spectra for these fuel assemblies are given in Tables 13.7-2, 13.7-3, and 13.7-4.

The source modeling methodology is similar to the one used for the NUHOMS-32P DSC. For the NUHOMS-32PHB DSC bounding gamma source terms, MCNP models were created to determine response functions for the modular constructed HSM-HB, as well as for the transfer cask in the forced-cooling configuration. Note that the purpose of analysis with MCNP was to determine a response function for identifying bounding gamma source terms and not to determine the actual dose rates reported later in this section. The gamma energy spectrum for analyzed fuel assemblies was multiplied by the response function to obtain the dose rates. The burnup and enrichment case which yielded the highest gamma dose rate were selected as the bounding gamma source terms.

Fuel assemblies meeting the requirements of Table 9.4-4 may be loaded into a NUHOMS-32PHB DSC and stored in the modular constructed HSM-HBs as long as the total heat load in the DSC is equal to or less than 29.6 kW (i.e., 12 fuel assemblies at 0.8 kW and 20 fuel assemblies at 1.0 kW).

This NUHOMS-32PHB DSC sources bound all fuel assemblies that have an initial U235 enrichment less than or equal to 5.0%, burnup less than or CALVERT CLIFFS ISFSI USAR 13.7-3 Rev. 26

equal to 62,000 MWD/MTU, and a thermal output less than or equal to 1.0 kW or less than or equal to 0.8 kW.

13.7.2.2 Airborne Radioactive Material Sources The discussion in USAR Section 7.2.2 is applicable to the NUHOMS-32PHB DSC and the HSM-HB.

13.7.3 RADIATION PROTECTION DESIGN FEATURES - NUHOMS-32PHB DSC 13.7.3.1 Installation Design Features The discussion referred to in USAR Section 7.3.1 is applicable to the NUHOMS-32PHB DSC, with the exception that the modular constructed HSM-HBs are used for storage instead of the concrete poured in place HSMs. Figure 1.2-1 is the layout and arrangement drawing for CCNPP ISFSI storage array with HSM-HB units. Radiation sources are contained within DSCs which are stored in concrete HSM-HBs. The radioactive sources for this ISFSI installation are described in USAR Section 13.7.2.

13.7.3.2 Shielding The shielding analyses for the NUHOMS-32PHB DSC are similar in form and methodology to the design basis analyses for the NUHOMS-24P DSC and the NUHOMS-32P DSC, with the exception that the basket of the NUHOMS-32PHB DSC is modeled explicitly and only the fuel is homogenized in the four axial fuel regions used previously for the NUHOMS-24P and NUHOMS-32P DSC (upper end fitting, plenum, active fuel, and bottom end fitting). The methodology and model are described in detail in References 13.30 and 13.31.

The results of the shielding analyses for the NUHOMS-32PHB DSC with the HSM-HB and the transfer cask in the forced-cooling configuration are presented in Table 13.7-1.

13.7.3.3 Ventilation The discussion in USAR Section 7.3.3 is generally applicable to the NUHOMS-32PHB DSC. The only differences are that the outlet vents are repositioned from their prior location on the top front and back of the HSM to the top sides of the HSM-HB (opening shared by adjacent modules).

Similarly, the inlet vents are repositioned from their prior location on the front bottom center of the HSM to the front bottom sides of the HSM-HB (opening shared by adjacent modules). In addition, the HSM-HB inlet vent may optionally utilize an alternative bird screen design with attenuation pipes attached to the inside of the bird screen (pipes are not credited for normal, off-normal or accident conditions). The attenuation pipes consist of three 14 Schedule 10 stainless steel pipes stacked in a triangular formation. The pipes have no significant impact on air flow, but reduce maximum gamma dose rates at the inlet vent by 43% (Reference 13.31, Table 12-2).

CALVERT CLIFFS ISFSI USAR 13.7-4 Rev. 26

13.7.3.4 Area Radiation and Airborne Radioactivity Monitoring Instrumentation The discussion in USAR Section 7.3.4 is applicable to the NUHOMS-32PHB DSC.

13.7.4 ESTIMATED ON-SITE COLLECTIVE DOSE ASSESSMENT 13.7.4.1 Operational Exposure The discussion of USAR Section 7.4.1 is applicable to the NUHOMS-32PHB DSC, the HSM-HB, and the transfer cask in the forced-cooling configuration.

13.7.4.2 Storage Term Exposure The discussion of USAR Section 7.4.2 is applicable to the NUHOMS-32PHB DSC, the HSM-HB, and the transfer cask in the forced-cooling configuration.

13.7.5 HEALTH PHYSICS PROGRAM The discussion in USAR Section 7.5 is applicable to the NUHOMS-32PHB DSC, the HSM-HB, and the transfer cask in the forced-cooling configuration.

13.7.6 ESTIMATED OFF-SITE COLLECTIVE DOSE ASSESSMENT 13.7.6.1 Effluent and Environmental Monitoring Program The discussion in USAR Section 7.6.1 is applicable to the NUHOMS-32PHB DSC and the HSM-HB.

13.7.6.2 Analysis of Multiple Contribution The discussion in USAR Section 7.6.2 is applicable to the NUHOMS-32PHB DSC and the HSM-HB.

13.7.6.3 Estimated Dose Equivalents The discussion in USAR Section 7.6.3 is applicable to the NUHOMS-32PHB DSC and the HSM-HB.

13.7.6.4 Liquid Release The discussion in USAR Section 7.6.4 is applicable to the NUHOMS-32PHB DSC and the HSM-HB.

CALVERT CLIFFS ISFSI USAR 13.7-5 Rev. 26

TABLE 13.7-1 NUHOMS-32PHB DSC SHIELDING ANALYSIS RESULTS - MAXIMUM DOSE RATES (mrem/hr)

Radial Gamma Radiation Neutron Radiation Total Distance, Dose Rate, Relative Dose Rate, Relative Dose Rate, Relative feet mrem/hr Error mrem/hr Error mrem/hr Error 0 211.6 0.02 3,381.4 0.003 3,520.6 0.003 0.67 122.2 0.02 2,357.8 0.003 2,471.3 0.003 1 108.1 0.02 2,035.2 0.003 2,137.7 0.003 1.5 92.3 0.02 1,673.3 0.003 1,763.0 0.003 3 64.9 0.02 1,018.9 0.003 1,083.0 0.003 4 53.8 0.02 769.0 0.003 822.8 0.003 5 45.0 0.02 598.9 0.003 643.8 0.003 6 38.2 0.02 476.4 0.003 514.6 0.003 8 28.3 0.02 320.4 0.003 348.4 0.003 15 12.8 0.02 118.2 0.004 131.0 0.004 Reference 13.30 Table 13-2 CALVERT CLIFFS ISFSI USAR 13.7-6 Rev. 26

TABLE 13.7-2 Neutron Source Terms (Neutron/Sec)

(BOUNDING FOR NUHOMS-32PHB DSC IN THE HSM-HB(a) and THE TRANSFER CASK(b))

Adjusted Group Upper Energy 1000 Watt 800 Watt 800 Watt(c)

Number (MeV) Neutrons/Sec Neutrons/Sec Neutrons/Sec 1 2.00E+01 0.000E+00 0.000E+00 0.000E+00 2 1.40E+01 1.175E+05 9.004E+04 9.463E+04 3 1.20E+01 7.200E+05 5.518E+05 5.800E+05 4 1.00E+01 2.440E+06 1.870E+06 1.965E+06 5 8.00E+00 1.973E+06 1.512E+06 1.589E+06 6 7.50E+00 2.636E+06 2.020E+06 2.123E+06 7 7.00E+00 3.901E+06 2.990E+06 3.143E+06 8 6.50E+00 5.829E+06 4.467E+06 4.695E+06 9 6.00E+00 8.736E+06 6.695E+06 7.037E+06 10 5.50E+00 1.175E+07 9.004E+06 9.463E+06 11 5.00E+00 1.627E+07 1.247E+07 1.311E+07 12 4.50E+00 2.125E+07 1.631E+07 1.714E+07 13 4.00E+00 3.424E+07 2.630E+07 2.764E+07 14 3.50E+00 4.236E+07 3.264E+07 3.431E+07 15 3.00E+00 5.511E+07 4.251E+07 4.468E+07 16 2.50E+00 2.084E+07 1.606E+07 1.688E+07 17 2.35E+00 2.917E+07 2.247E+07 2.362E+07 18 2.15E+00 2.319E+07 1.786E+07 1.877E+07 19 2.00E+00 3.385E+07 2.604E+07 2.737E+07 20 1.80E+00 2.616E+07 2.011E+07 2.114E+07 21 1.66E+00 1.741E+07 1.337E+07 1.405E+07 22 1.57E+00 1.452E+07 1.116E+07 1.173E+07 23 1.50E+00 1.241E+07 9.529E+06 1.002E+07 24 1.44E+00 2.486E+07 1.909E+07 2.006E+07 25 1.33E+00 3.075E+07 2.359E+07 2.479E+07 26 1.20E+00 4.783E+07 3.669E+07 3.856E+07 27 1.00E+00 4.654E+07 3.568E+07 3.750E+07 28 8.00E-01 2.687E+07 2.060E+07 2.165E+07 29 7.00E-01 2.684E+07 2.057E+07 2.162E+07 30 6.00E-01 2.309E+07 1.770E+07 1.860E+07 31 5.12E-01 5.247E+05 4.022E+05 4.227E+05 32 5.10E-01 1.574E+07 1.206E+07 1.268E+07 33 4.50E-01 1.311E+07 1.005E+07 1.056E+07 34 4.00E-01 2.533E+07 1.941E+07 2.040E+07 35 3.00E-01 5.225E+03 4.716E+03 4.957E+03 36 2.00E-01 2.613E+03 2.358E+03 2.478E+03 37 1.50E-01 2.613E+03 2.358E+03 2.478E+03 38 1.00E-01 0.000E+00 0.000E+00 0.000E+00 39 7.50E-02 0.000E+00 0.000E+00 0.000E+00 40 7.00E-02 0.000E+00 0.000E+00 0.000E+00 41 6.00E-02 0.000E+00 0.000E+00 0.000E+00 42 4.50E-02 0.000E+00 0.000E+00 0.000E+00 CALVERT CLIFFS ISFSI USAR 13.7-7 Rev. 26

TABLE 13.7-2 Neutron Source Terms (Neutron/Sec)

(BOUNDING FOR NUHOMS-32PHB DSC IN THE HSM-HB(a) and THE TRANSFER CASK(b))

Adjusted Group Upper Energy 1000 Watt 800 Watt 800 Watt(c)

Number (MeV) Neutrons/Sec Neutrons/Sec Neutrons/Sec 43 3.00E-02 0.000E+00 0.000E+00 0.000E+00 44 2.00E-02 0.000E+00 0.000E+00 0.000E+00 Total 6.664E+08 5.119E+08 5.380E+08 For more information see Reference 13.1.

(a) The modular constructed HSM-HB.

(b) Transfer cask in the forced-cooling configuration.

(c) The neutron sources for the 0.8 kW are conservatively scaled up to bound the standard fuel.

CALVERT CLIFFS ISFSI USAR 13.7-8 Rev. 26

TABLE 13.7-3 Gamma Source Terms for 1.0 kW (BOUNDING FOR NUHOMS-32PHB DSC IN THE HSM-HB(a) and THE TRANSFER CASK(b))

Upper Bottom End Top End Group Energy Active Fuel Fitting Plenum Fitting Total Number (MeV) Gamma/sec Gamma/sec Gamma/sec Gamma/sec Gamma/sec MeV/sec 1 2.00E-02 1.8309E+15 1.1975E+12 2.6007E+11 5.9645E+11 1.8329E+15 1.8329E+13 2 3.00E-02 4.0336E+14 5.0116E+12 1.4867E+11 4.9134E+12 4.1343E+14 1.0336E+13 3 4.50E-02 4.7812E+14 9.5228E+11 4.5905E+10 8.8477E+11 4.8000E+14 1.8001E+13 4 7.00E-02 3.2245E+14 9.0541E+10 2.3267E+10 3.2518E+10 3.2260E+14 1.8549E+13 5 1.00E-01 2.3072E+14 4.3150E+10 1.1047E+10 1.5604E+10 2.3079E+14 1.9618E+13 6 1.50E-01 2.5838E+14 4.1052E+10 5.7417E+09 2.7865E+10 2.5846E+14 3.2307E+13 7 3.00E-01 2.0693E+14 3.0845E+11 8.0501E+09 3.0519E+11 2.0755E+14 4.6699E+13 8 4.50E-01 1.1069E+14 1.8091E+12 4.0435E+10 1.8085E+12 1.1434E+14 4.2879E+13 9 7.00E-01 2.7885E+15 2.3256E+12 5.1568E+10 2.3255E+12 2.7932E+15 1.6061E+15 10 1.00E+00 6.4182E+14 1.1389E+11 1.4123E+11 1.5876E+10 6.4209E+14 5.4578E+14 11 1.50E+00 1.1430E+14 2.4863E+13 8.8480E+12 2.2137E+12 1.5023E+14 1.8779E+14 12 2.00E+00 4.9356E+12 1.9702E+04 8.7286E+03 5.2170E+03 4.9356E+12 8.6373E+12 13 2.50E+00 3.8170E+12 1.3123E+08 4.6700E+07 1.1684E+07 3.8172E+12 8.5888E+12 14 3.00E+00 1.0030E+11 2.0348E+05 7.2413E+04 1.8117E+04 1.0030E+11 2.7584E+11 15 4.00E+00 1.2406E+10 1.5404E-09 1.7135E-13 2.1771E-12 1.2406E+10 4.3420E+10 16 6.00E+00 6.8458E+06 0.0000E+00 0.0000E+00 0.0000E+00 6.8458E+06 3.4229E+07 17 8.00E+00 7.8837E+05 0.0000E+00 0.0000E+00 0.0000E+00 7.8837E+05 5.5186E+06 18 1.10E+01 9.0680E+04 0.0000E+00 0.0000E+00 0.0000E+00 9.0680E+04 8.6146E+05 Total 7.3950E+15 3.6756E+13 9.5840E+12 1.3139E+13 7.4545E+15 2.5640E+15 For more information see Reference 13.1.

(a) The modular constructed HSM-HB.

(b) Transfer cask in the forced-cooling configuration.

CALVERT CLIFFS ISFSI USAR 13.7-9 Rev. 26

TABLE 13.7-4 Gamma Source Terms for 0.8 kW (BOUNDING FOR NUHOMS-32PHB DSC IN THE HSM-HB(a) and THE TRANSFER CASK(b)

Upper Bottom End Top End Group Energy Active Fuel Fitting Plenum Fitting Total Number (MeV) Gamma/sec Gamma/sec Gamma/sec Gamma/sec Gamma/sec MeV/sec 1 2.00E-02 1.5125E+15 9.7577E+11 2.1445E+11 4.7483E+11 1.5142E+15 1.5142E+13 2 3.00E-02 3.3255E+14 3.9578E+12 1.1892E+11 3.8756E+12 3.4051E+14 8.5125E+12 3 4.50E-02 3.9444E+14 7.7666E+11 3.7880E+10 7.2024E+11 3.9597E+14 1.4849E+13 4 7.00E-02 2.6589E+14 7.4854E+10 1.9376E+10 2.6379E+10 2.6601E+14 1.5295E+13 5 1.00E-01 1.8874E+14 3.5761E+10 9.2020E+09 1.2748E+10 1.8879E+14 1.6048E+13 6 1.50E-01 2.0785E+14 3.3716E+10 4.7739E+09 2.2699E+10 2.0791E+14 2.5988E+13 7 3.00E-01 1.6860E+14 2.5111E+11 6.5768E+09 2.4838E+11 1.6911E+14 3.8049E+13 8 4.50E-01 8.9579E+13 1.4724E+12 3.2917E+10 1.4719E+12 9.2556E+13 3.4708E+13 9 7.00E-01 2.2569E+15 1.8929E+12 4.1972E+10 1.8927E+12 2.2607E+15 1.2999E+15 10 1.00E+00 4.6266E+14 8.4611E+10 1.0470E+11 1.1775E+10 4.6286E+14 3.9344E+14 11 1.50E+00 8.6705E+13 2.0769E+13 7.3749E+12 1.8475E+12 1.1670E+14 1.4587E+14 12 2.00E+00 3.7017E+12 8.5923E+03 4.0391E+03 1.9076E+03 3.7017E+12 6.4779E+12 13 2.50E+00 2.9071E+12 1.0962E+08 3.8925E+07 9.7514E+06 2.9073E+12 6.5413E+12 14 3.00E+00 7.1891E+10 1.6998E+05 6.0357E+04 1.5120E+04 7.1891E+10 1.9770E+11 15 4.00E+00 8.8689E+09 5.2264E-10 1.0373E-13 1.3202E-12 8.8689E+09 3.1041E+10 16 6.00E+00 3.4765E+06 0.0000E+00 0.0000E+00 0.0000E+00 3.4765E+06 1.7382E+07 17 8.00E+00 4.0028E+05 0.0000E+00 0.0000E+00 0.0000E+00 4.0028E+05 2.8020E+06 18 1.10E+01 4.6037E+04 0.0000E+00 0.0000E+00 0.0000E+00 4.6037E+04 4.3736E+05 Total 5.9732E+15 3.0325E+13 7.9657E+12 1.0605E+13 6.0220E+15 2.0210E+15 For more information see Reference 13.1 (a) The modular constructed HSM-HB.

(b) Transfer cask in the forced-cooling configuration.

CALVERT CLIFFS ISFSI USAR 13.7-10 Rev. 26

13.8 ACCIDENT ANALYSIS - NUHOMS-32PHB DSC Analyses of all design events for the NUHOMS-32P DSC have been reanalyzed for the NUHOMS-32PHB DSC. The results are reported in this section in the same format as in Section 12.8. The analytical assumptions, methodology, and computer codes used to generate the results in this section are identical to those used in Section 12.8 unless otherwise noted in the text.

13.8.1 NORMAL AND OFF-NORMAL OPERATIONS This section includes the evaluation of the normal and off-normal events for the NUHOMS-32PHB DSC.

13.8.1.1 Normal Operation Structural Analysis The normal operating loads for the NUHOMS-32PHB DSC important-to-safety components are shown in Reference 13.2, Table 7-1. A comprehensive structural analysis of the NUHOMS-32PHB DSC was performed and documented in Reference 13.6.

13.8.1.1.1 Normal Operation Structural Analysis The loads applicable to the normal operation structural analysis are calculated as described in detail in USAR Section 8.1.1.1, with the following exceptions:

A. Dead Weight Loads No exceptions B. Design Basis Internal Pressure Loads

- 15 psig (Normal), 20 psig (Off-normal), 100 psig (Accident). The assumed fuel rod average burnup is increased to 60 GWD/MTU (Standard and VAP fuels) and 62 GWD/MTU (AREVA fuel).

C. Design Basis Thermal Loads

- Ambient temperature -8°F to 104°F. The long-term average temperature assumed fuel rod average burnup is increased to 60 GWD/MTU (Standard and VAP fuels) and 62 GWD/MTU (AREVA fuel).

D. Operational Handling Loads The significant operational handling load is the sliding transfer of the DSC from the cask to the DSC support rails in the horizontal storage module (HSM). Since the Calvert Cliffs DSC weighs less than that of the generic DSC design, these loads are consistent with those in Reference 8.1, Section 8.1.1.4.B.

E. Design Basis Live Loads Live loads for the Calvert Cliffs ISFSI are enveloped by the generic live load of 200 lbf/ft2 used in Reference 8.1, Section 8.1.1.5.A.

CALVERT CLIFFS ISFSI USAR 13.8-1 Rev. 26

13.8.1.1.2 NUHOMS-32PHB DSC Analysis Stresses were evaluated in the DSC due to:

A. Dead Weight Loads B. Design Basis Normal Operating Internal Pressure Loads C. Normal Operating Thermal Loads D. Normal Operation Handling Loads The NUHOMS-32PHB DSC is analyzed using analytical methods comparable to those described for the NUHOMS-32P DSC in USAR Section 12.8. The ANSYS analytical model used for the analysis of dead weight, pressure, thermal, and handling loads is similar to that used in the evaluation of the NUHOMS-32P. The ANSYS analysis model is described in Reference 13.6. Stresses due to normal operating pressures are based on a bounding internal pressure of 15 psig (Reference 13.6, Table 4-3), applied as a uniform load to the inner boundary of the analytical model. Also considered was the external hydrostatic pressure loading on the DSC shell, when the annulus between the DSC shell and the transfer cask is filled with water. Circumferential shell temperature variations are analyzed using the ANSYS three-dimensional solid shell model. The NUHOMS-32PHB DSC stresses remain within ASME code allowable stresses (Reference 13.6).

13.8.1.1.3 NUHOMS-32PHB DSC Internal Basket Analysis The DSC basket analysis was performed for:

A. Dead Weight Loads B. Thermal Loads The fuel assembly weight of 1,375 lbs (Reference 13.2, Table 4-2) and 158 length (Reference 13.2, Table 4-2) are used in the analysis. The basket temperature is taken as 650°F uniform. The peripheral rail temperature is taken as 500°F uniform (Reference 13.7).

The three-dimensional finite element analysis ANSYS model used in the evaluation is described in Reference 13.7, Section 5.1. The analysis model consists of a 10.28 slice of the NUHOMS-32PHB DSC basket, rails, and canister using SHELL 43 elements, with appropriate boundary conditions applied at the cut faces of the model. The fuel assembly and aluminum plates are not included in the analysis model. The fuel assembly weight is applied as pressure on the basket plates. The weight of the aluminum plates is accounted for by increasing the density of stainless steel tubes. The aluminum plate stiffness is conservatively neglected in the analysis. The fusion welds connecting the fuels compartment guide sleeves CALVERT CLIFFS ISFSI USAR 13.8-2 Rev. 26

and the bolts connecting the rails are modeled by three-dimensional PIPE16 elements. Gap elements (CONTACT 52) are used to simulate the interface between the basket rails and inner side of canister as well as between outer side of canister and inside of transfer cask.

The results of the analysis show that the stresses in the DSC are within the allowable stress limits (Reference 13.6).

13.8.1.1.4 NUHOMS-32PHB DSC Support Assembly Analysis The DSC support assembly inside a modular constructed HSM-HB, for the NUHOMS-32PHB DSC, was evaluated for the loads listed below. The allowable stresses are taken at a bounding temperature of 300°F for all conditions, including normal operation (Reference 13.10).

A. Dead Weight Loads B. Normal Operational Handling Loads C. Thermal Loads The calculated stresses were small and meet all code allowables. (Reference 13.10) 13.8.1.1.5 Modular Constructed HSM-HB Analysis The HSM-HB arrangement used for the NUHOMS-32PHB DSC analysis is that of two, 1x12, back-to-back arrays and one array of 1x12 HSM-HBs. The following loads are considered in the structural analysis for normal operation loads for the modular constructed HSM-HBs.

A. Modular Constructed HSM-HB Dead and Live Loads The HSM-HB dead and live loads were evaluated using the ANSYS methodology as discussed in Reference 13.10 for the NUHOMS-32PHB DSC.

B. Concrete Creep and Shrinkage Loads Creep and shrinkage reduces the thermal expansive stresses. Therefore, in the evaluation performed in Reference 13.10, conservatively, the concrete creep and shrinkage forces are neglected. Also, the HSM-HB design satisfies the minimum reinforcement requirements of ACI 349-97 which is partly based on creep and shrinkage considerations (Reference 13.10).

CALVERT CLIFFS ISFSI USAR 13.8-3 Rev. 26

C. Modular Constructed HSM-HB Thermal Loads The HSM-HB thermal loads, temperature-dependent material properties, analysis approach, and analysis results are documented in Reference 13.44.

Conservatively, a maximum heat load of 29.6 kW per DSC is used for all conditions, including normal operation (References 13.44 and 13.23).

D. Radiation Effect on Modular Constructed HSM-HB Concrete The effects of radiation on the original poured in place HSM concrete were determined to be negligible for the NUHOMS-24P DSC in Reference 13.45, Section 8.1.1.5.D. The effect of radiation on the modular constructed HSM-HB concrete remains negligible for the NUHOMS-32PHB DSC. The neutron fluence from the NUHOMS-32PHB DSC remains below the threshold for neutron induced degradation of concrete and the gamma flux is less than the NUHOMS-24P DSC value (References 13.45 and 13.59).

E. Modular Constructed HSM-HB Design Analysis Structural evaluation of the modular constructed HSM-HB concrete structure, DSC support structure, heat shield, and miscellaneous components for the NUHOMS-32PHB DSC are documented in Reference 13.10.

The results of the evaluation confirm that the normal operation moment and shear in the modular constructed HSM-HB concrete structure are less than the ultimate moment and shear capacity, as shown in Reference 13.10.

13.8.1.1.6 Modular Constructed HSM-HB Door Analysis The HSM-HB front shield door is a composite door, which consists of a rectangular steel face plate at the front attached to a circular reinforced concrete block at the rear. The circular concrete block is inset into the HSM-HB doorway and the rectangular steel face plate of the door is attached to the front wall concrete using four bolts anchored through four embedments.

The shield door is free to grow in the radial direction when subjected to thermal loads. Therefore, there will be no stresses in the door due to thermal growth. The dead weight, tornado wind, differential pressure, and flood loads cause insignificant stresses in the door compared to stresses due to missile impact CALVERT CLIFFS ISFSI USAR 13.8-4 Rev. 26

load. Therefore, the door is evaluated only for the missile impact load. The computed maximum ductility ratio for the door is less than 1 (compared to the allowable ductility of 20)

(Reference 13.10, Section 10.2.5 Part A). For the door anchorage, the controlling load is tornado generated differential pressure drop load. The maximum tensile force per bolt (there are four bolts that attach the door assembly to the front concrete wall of the HSM-HB) is 4.5 kips. This is less than the allowable load per bolt of 44.3 kips (Reference 13.10, Section C6.2). The concrete pullout strength is conservatively estimated as 24 kips which is greater than the ultimate capacity of the four bolts, thus satisfying the ductility requirements of the ACI Code.

13.8.1.1.7 Heat Shield Analysis The discussion in Section 8.1.1.7 is applicable to the NUHOMS-32P DSC in the HSM. Similar to the HSM, the HSM-HB provides flat stainless steel heat shields on the side walls of the base unit and under the roof.

The HSM-HB top heat shield consists of two heat shield panels.

Each panel has a 12 gauge 304 stainless steel sheet which is 0.1054" thick. Both the panels of the roof heat shield are suspended from the roof by fifteen rods of 1/2 diameter ASTM A193, Grade B7 in three rows, bolted to the sheets.

The combined axial and bending stress in the rods is 59.5 ksi.

The allowable stress is 70.2 ksi (Reference 13.10, B5.1). The HSM-HB side heat shield consists of four 12 gauge 304 stainless steel heat shield supported off the base unit side wall by thirty four rod stand-offs threaded into concrete embedments. The maximum axial and bending stress in the rods is about 1.4 ksi and 79.3 ksi, respectively. The axial and bending stress allowable for the rods is 67.9 ksi and 112.3 ksi, respectively (Reference 13.10, B5.2). The maximum temperature used in the stress analysis of the heat shields is 270°F (Reference 13.10, B3.1), which bounds the temperatures determined for storage of the NUHOMS-61BTH DSC for normal and off-normal conditions (Reference 13.44).

13.8.1.1.8 HSM-HB Seismic Restraint for DSC The seismic restraint consists of a tube steel embedment located within the bottom center of the round access opening of the HSM-HB, and a tube steel retainer assembly that drops into the embedment cavity after the NUHOMS-32PHB DSC transfer is complete. The drop-in retainer extends approximately 4 above the rail to provide axial restraint of the NUHOMS-32PHB DSC. Details of the analysis of the CCNPP DSC seismic restraint is provided in Reference 13.10.

CALVERT CLIFFS ISFSI USAR 13.8-5 Rev. 26

13.8.1.1.9 Transfer Cask Forced-cooling Configuration Analysis The transfer cask in the forced-cooling configuration was re-evaluated (Reference 13.26) for the normal operation loads identified in USAR Section 8.1.1.9, with the following differences:

A. Transfer Cask Dead Weight Loads The analysis methodology is the same as in USAR Section 8.1.1.9, but additional weight was considered due to increased mass of the NUHOMS-32PHB DSC payload and the supporting equipment. Associated analysis is presented in References 13.3 and 13.13.

B. Transfer Cask Normal Handling Loads The analysis methodology is the same as in USAR Section 8.1.1.9, but the transfer handling stresses are calculated for cask loading and unloading into a modular constructed HSM-HB. Associated analysis is presented in References 13.8 and 13.2, Table 8-11.

C. Transfer Cask Normal Operation Thermal Loads The analysis methodology is the same as in USAR Section 8.1.1.9, but the thermal loads are calculated assuming 29.6 kW decay heat power.

Additionally, heat removal due to forced cooling is incorporated into the analysis and is further described in References 13.22 and 13.26, Section 4.4.

A bounding design temperature of 570°C is used for both normal and off-normal operating conditions (Reference 13.26).

The resulting maximum dead weight, thermal, and handling stresses in the transfer cask and its components are within the allowable stress limits.

13.8.1.2 Off-Normal Load Structural Analysis The off-normal loads for the NUHOMS-32PHB DSC are identified in USAR Section 8.1.2. A detailed analysis is provided in References 13.6 and 13.10.

13.8.1.2.1 Jammed NUHOMS-32PHB DSC During Transfer with Self-Propelled Modular Transporter This off-normal condition results from the DSC becoming jammed in the transfer cask or the modular constructed HSM-HB during the transfer operation.

A. Postulated Cause of Jammed DSC If the transfer cask is not accurately aligned with the HSM-HB, the DSC might become bound or jammed during the transfer operation. The maximum tolerable CALVERT CLIFFS ISFSI USAR 13.8-6 Rev. 26

misalignment for the DSC insertion operation into the modular constructed HSM-HB is +/- 0.25 as discussed in Reference 13.45.

B. Detection of Jammed DSC When DSC jamming occurs, the hydraulic pressure in the ram will increase. When the hydraulic pressure corresponds to a force on the DSC of 80,000 lbf, the DSC will be presumed to be jammed (Reference 13.2, Table 8-11). The normal pushing and pulling forces will be limited to 23,750 lbf with a ram system design capability of up to 95,000 lbf (Reference 13.2, Table 8-11).

C. Analysis of Effects and Consequences The analyses of the NUHOMS-32PHB DSC under the assumed jamming and binding conditions are documented Reference 13.6.

The stresses on the NUHOMS-32PHB DSC body have been analyzed for a maximum ram force of 95,000 lbf (Reference 13.6). The calculated stresses were significantly less than the ASME code allowable stress criteria. Therefore, plastic deformation of the NUHOMS-32PHB DSC body will not occur and there is no potential for rupture.

Since the maximum NUHOMS-32PHB DSC stresses applied to a jammed NUHOMS-32PHB DSC generated from the maximum ram force is within the design basis limits of the DSC, there are no dose (airborne release) consequences associated with the postulated jammed NUHOMS-32PHB DSC during HSM-HB loading.

D. Corrective Actions The courses of action open to the system operators to correct a jammed NUHOMS-32PHB DSC are described in USAR Section 8.1.2.1.D.

13.8.1.2.2 Off-Normal Thermal Loads Analysis Structural analyses of the ISFSI components for off-normal thermal loads are discussed below using the temperature extremes of -8°F and 104°F (References 13.6 and 13.44).

A. HSM-HB Off-Normal Thermal Analysis The methodology used for the off-normal thermal loads structural analysis of the HSM-HB concrete structure storing the loaded NUHOMS-32PHB DSC is the same as for the normal thermal loads structural analysis of the structure described in USAR Section 13.8.1.1.5.C.

CALVERT CLIFFS ISFSI USAR 13.8-7 Rev. 26

The DSC support assembly is designed with slotted holes as described in Section 9 of Reference 13.10; and therefore, the increase in temperature has no effect on the DSC support structure.

B. DSC Off-Normal Thermal Analysis Off-normal thermal loads structural analysis of the NUHOMS-32PHB DSC shell assembly and the DSC fuel basket assembly for the DSC inside the HSM-HB are performed using the same methodology as for the normal thermal loads structural analyses of these components.

As discussed in USAR Section 13.8.1.1.9, the off-normal thermal loads for the transfer cask are identical to the normal thermal loads. Therefore, the off-normal thermal loads for the DSC inside the transfer cask are identical to the normal thermal loads for the DSC inside the transfer cask, and are not considered further.

C. Transfer Cask Off-Normal Thermal Analysis As previously stated, the off-normal thermal loads for the transfer cask are identical to the normal thermal loads. Therefore, the off-normal thermal loads for the transfer cask are not considered further.

13.8.1.3 Thermal Hydraulic Analyses The following evaluations have been performed for the CCNPP ISFSI:

A. Thermal Analysis of the modular constructed HSM-HB B. Thermal Analysis of the NUHOMS-32PHB DSC in the HSM-HB C. Thermal Analysis of the NUHOMS-32PHB DSC in the Transfer Cask (forced-cooling configuration)

The analytical models of the HSM-HB, the NUHOMS-32PHB DSC, and the transfer cask in the forced-cooling configuration are described in References 13.44 (HSM-HB), 13.23 (DSC in the HSM-HB), and 13.23 (DSC in the transfer cask).

The method described in Reference 13.27 is used for calculating the effective thermal conductivity of the spent fuel assemblies.

The HSM-HB and CCNPP forced cooling transfer cask and NUHOMS-32PHB DSC are based on 3D models (Reference 13.42).

The HSM-HB and CCNPP forced cooling transfer cask were evaluated to determine the DSC shell temperatures. These temperatures were used on the NUHOMS-32PHB DSC model to determine the fuel cladding temperature. The same approach was used to evaluate the 32P.

CALVERT CLIFFS ISFSI USAR 13.8-8 Rev. 26

The primary portion of the thermal evaluation of the NUHOMS-32PHB DSC design uses a methodology that differs from the thermal analysis methodology utilized for the NUHOMS-24P DSC. The NUHOMS-32PHB DSC thermal methodology has three major new features:

• Solution Method - ANSYS finite element

• Model Geometry - 3D

• Treatment of Effective Transverse Thermal Conductivity of Fuel - A detailed finite element model of the spent fuel according to method of the TRW Spent Nuclear Fuel Effective Conductivity Report (Reference 13.27)

The new methodology has been compared in detail with the methodology used for the thermal analysis of the Transnuclear NUHOMS-32PT DSC design which was used and approved by the Nuclear Regulatory Commission (NRC) in Amendment 8 and Amendment 10 to CoC 1004. The use of the NUHOMS-32PT DSC methodology is appropriate for the CCNPP ISFSI with the NUHOMS-32PHB DSC.

The radial effective thermal conductivity for helium backfill conditions is determined by creating a two-dimensional finite element ANSYS model of the fuel assembly centered within a basket compartment. The outer surfaces, representing the fuel compartment walls, are held at a constant temperature, and decay heat is applied to the fuel pellets within the model.

A maximum fuel assembly temperature is then determined. From the heat load, maximum fuel temperature, and outer surface temperature, the effective fuel conductivity can be determined via an equation given in Reference 13.27, Section 8.1.

The axial effective conductivity (Kaxl) is determined directly from the geometry and conductivities of the fuel components.

Mass-weighted averages are used in the determination of the effective density (eff) and specific heat values (Cp,eff).

The effective properties of the fuel are shown in Reference 13.27.

The thermal analyses are performed with the following ambient air temperatures:

A. Normal Conditions The ambient temperature range for the NUHOMS-32PHB DSC, thermal analysis is -8°F to 104°F. Detailed analysis is discussed in Reference 13.23.

B. Off-Normal Condition The off-normal ambient temperature range for the NUHOMS-32PHB DSC, thermal analysis is -8°F to 104°F (References 13.10 and 13.44). A solar heat flux of 127 Btu/hr-ft2 is included in the analysis as discussed in Reference 13.22.

CALVERT CLIFFS ISFSI USAR 13.8-9 Rev. 26

C. Accident Condition An extreme summer condition with an ambient temperature of 105°F was considered in Reference 13.23, Table 6-2. In addition, the HSM-HB vents are assumed to be completely blocked for a period of 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> (Reference 13.23, Table 6-2). A solar heat flux of 127 Btu/hr-ft2 is conservatively included to maximize the HSM-HB concrete temperatures.

A fire accident is considered for the Transfer Cask under Reference 13.22.

After initiation of forced cooling of the transfer cask, if a malfunction of that system were to occur, up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> are available to complete the transfer, restart the fans, or fill the transfer cask/DSC annulus with water (Reference 13.21). To minimize the occurrence of malfunction of the forced cooling system, the self-propelled modular transporter is equipped with redundant industrial grade blowers, each of which is capable of supplying the required minimum air flow rate, as well as a redundant power supply for the blowers.

13.8.1.3.1 Thermal Analysis of the Modular Constructed HSM-HB The modular constructed HSM-HB thermal analyses are performed for the ambient air temperatures defined in USAR Section 13.8.1.3.

The decay heat load is transferred from the DSC to the HSM-HB air space by convection and then is removed from the HSM-HB by natural convection air flow. Heat is also radiated from the DSC surface to the heat shield and HSM-HB walls where the natural convection air flow removes the heat. The solar heat flux is applied to the HSM-HB roof and front wall.

Heat transfer from the outer surface of the HSM-HB roof and front wall is by natural convection and radiation to the ambient air. Heat transfer from the HSM-HB concrete foundation slab is by conduction to the soil below.

Maximum temperatures on the DSC outer surfaces and the concrete inner and outer surfaces are calculated for the normal, off-normal winter, and off-normal summer ambient conditions, and the postulated accident conditions with blocked HSM-HB vents (References 13.44 and 13.23).

13.8.1.3.2 Thermal Analysis of the DSC in the HSM-HB The DSC and fuel assembly heat transfer analysis with the DSC inside the HSM-HB was performed for the ambient air temperatures defined in USAR Section 13.8.1.3. The analytical model is described in Reference 13.44. The cases of interest are those that maximize fuel cladding temperature (summer ambient conditions) as described in Reference 13.23.

CALVERT CLIFFS ISFSI USAR 13.8-10 Rev. 26

In the analysis, an effective conductivity is determined for the aluminum/poison plates and is substituted for that of the all-aluminum interior basket plates in the model from Reference 13.23, Section 5.2. The modified model is run for normal, off-normal, and blocked vent conditions. The analysis shows that the modified plates have a negligible impact on maximum component temperatures. The temperatures from these cases are used to derive the DSC internal pressures in Reference 13.24.

The maximum allowable fuel cladding temperature for long-term storage is 400°C which is greater than 335°C value discussed in USAR Section 8.1.3.2.

The acceptable peak fuel clad temperature limit for accident conditions for ISFSI storage is 1,058°F (570°C)

(Reference 13.23). This limit is based on the empirical work presented in NRC Interim Staff Guidance (ISG)-11 and incorporated in NUREG-1536, Revision 1. The peak fuel clad temperature limit (short-term) of 570°C (1,058°F) is specified in the off-normal DSC thermal calculation (Reference 13.23).

13.8.1.3.3 Thermal Analysis of the DSC in the Transfer Cask The thermal analyses for the cases with the DSC inside the transfer cask are performed for the ambient air temperatures defined in USAR Section 13.8.1.3. The analyses are conducted using the model described in Reference 13.23, Section 6.0.

In the models presented in Reference 13.22, Section 3.1, the gap size between the inner shell of the transfer cask and the outer shell of the DSC is assumed uniform in all directions. For horizontal orientation the gap varies from bottom to top (Reference 13.22, Sections 3.1 and 5.1). For the asymmetries and gap sizes investigated, there is little impact on the maximum component temperatures.

References 13.23 evaluate the impact of aluminum/poison material plates in the basket on the maximum component temperatures. In the analysis, an effective conductivity is determined for the aluminum/poison plates and is substituted for that of the all-aluminum interior basket plates in the models from Reference 13.23. The analysis shows that the modified plates have a negligible impact on maximum component temperatures.

Use of NS-3 for the transfer cask neutron shield is discussed in USAR Section 8.1.3.3.

CALVERT CLIFFS ISFSI USAR 13.8-11 Rev. 26

13.8.1.3.4 Thermal Analysis of the DSC in the Transfer Cask with Loss of Forced Cooling The postulated loss of forced airflow condition considers an evaluation of the system performance for the case wherein steady-state conditions are established with the fan in operation and, subsequently the fan airflow is lost (Reference 13.21).

This analysis presents a time limit to restore the forced airflow or to complete the transfer of the NUHOMS-32PHB DSC with 29.6 kW heat load to the HSM-HB concrete module. The time limit is selected such that the peak fuel cladding temperature will remain below the normal/off-normal cladding temperature limit of 752°F for transfer operations as recommended in NRC ISG-11, Revision 3. The selected time limit is bounding for NUHOMS-32PHB system with heat loads at or less than 29.6 kW.

13.8.2 ACCIDENTS This section addresses design events of the third and fourth types as defined by ANSI/American Nuclear Society 57.9-1984, and other credible accidents consistent with 10 CFR Part 72 which could impact the safe operation of the CCNPP ISFSI. The postulated events identified in USAR Section 12.8.2 and Reference 13.10, Section 7.1 and addressed for the CCNPP ISFSI are:

A. Loss of Air Outlet Shielding B. Tornado Winds/Tornado Missile C. Earthquake D. Flood E. Transfer Cask Drop F. Lightning G. Blockage of Air Inlets and Outlets H. DSC Leakage I. Accidental Pressurization of DSC In addition, two additional CCNPP site-specific accidents have been identified and addressed. These are:

A. Forest Fire B. Liquified Natural Gas Plant or Pipeline Spill or Explosion In the following sections, each accident condition is evaluated for applicability to the CCNPP ISFSI. For each applicable condition the accident cause, structural, thermal, radiological consequences, and recovery measures required to mitigate the accident are discussed. Where appropriate, resulting accident condition stresses were combined with those of normal operating loads in accordance with the load combination definitions of USAR Section 13.3.2.5. Load combination results for the HSM-HB, NUHOMS-32PHB DSC, and transfer cask in the forced-cooling configuration are discussed in USAR Section 13.8.2.12.

Reflood pressure is included as an ASME Service Level D activity but is not identified as an accident.

CALVERT CLIFFS ISFSI USAR 13.8-12 Rev. 26

13.8.2.1 Loss of Air Outlet Shielding Loss of Air Outlet Shielding, is evaluated for the CCNPP NUHOMS-24P DSC in Section 8.2.1 of the ISFSI USAR. This accident was considered not credible for the current CCNPP HSMs because the air outlet shielding is designed to remain in place and withstand all design events including the effects of tornado missiles. Reference 13.36 (Section P.11.2.1.1) indicates that this accident is also not credible for the general license HSM-H design, which is structurally identical to the HSM-HB to be used at the CCNPP ISFSI.

Furthermore, Reference 13.10, Section 12.3 demonstrates that the HSM-HB air outlet vent concrete covers are also designed to remain in place and withstand all design events including the effects of tornado missiles.

Therefore, the conclusion that the loss of air outlet shielding accident is not credible remains valid for the HSM-HB.

13.8.2.2 Tornado Winds/Tornado Missile The structural analysis of the HSM-HB concrete structure, DSC supports, and miscellaneous structural steel components of the HSM-HB storing the NUHOMS-32PHB DSC confirm the structural integrity of the HSM-HB under all normal operations, off-normal operations, and accident conditions, including tornado wind/missile (Reference 13.10).

In addition, a tornado wind/missile overturning analysis for the transfer cask is presented in USAR Section 8.2.2 for the NUHOMS-24P DSC and USAR Section 12.8.2.2 for the NUHOMS-32P DSC. Analyses performed for the NUHOMS-32PHB DSC and the forced cooling transfer cask confirm that this conclusion continues to apply for transport of those structure, system, and components using the original skid/trailer (Reference 13.16). For transport of these structure, system, and components, as well as the NUHOMS-24P and NUHOMS-32P DSCs and the transfer cask in its original configuration, using the new transfer cask support skid and self-propelled modular transporter, Reference 13.41 demonstrates that similar overturning margin exists for tornado wind/missile loading.

13.8.2.3 Earthquake 13.8.2.3.1 Cause of Accident As specified in USAR Section 3.2.3, a Design Basis Earthquake with peak ground acceleration values of 0.15g horizontal and 0.10g vertical is postulated to occur at the CCNPP ISFSI.

13.8.2.3.2 Accident Analysis A. NUHOMS-32PHB DSC Seismic Analysis

1. DSC Seismic Analysis Inside the HSM-HB the combined earthquake load of 0.41g transverse, 0.36g axial, and 0.25g vertical is applied to the finite element model depicting the horizontal orientation of the DSC in storage. In addition to the seismic loads, 1.0g CALVERT CLIFFS ISFSI USAR 13.8-13 Rev. 27

vertical acceleration is added to account for the self-weight effects (Reference 13.6, Table 4-3).

A three-dimensional finite element model of the basket, rails, and the DSC canister was constructed by using the ANSYS computer program. Since the seismic loading is non-symmetric, a 360 model is used. Details of the analysis model and boundary conditions used are described in Reference 13.7. The finite element model used in the seismic analysis is shown in Reference 13.7, Section 5.1.

A nonlinear stress analysis is conducted for computing the elastic stresses in basket and canister shell models using ANSYS computer program. The nonlinearity of analysis results from the gap elements used in the analysis model. Details of the analysis are documented in Reference 13.6 for the DSC canister and Reference 13.7 for the DSC basket assembly.

The resulting maximum stresses in the DSC canister and in the DSC basket assembly remain within the specified ASME code allowable stress criteria.

2. DSC Seismic Stability Analysis An evaluation for the potential of the NUHOMS-32PHB DSC to lift-off from the DSC support assembly rail during a seismic event is documented in Reference 13.10, Section 5.9.

The seismic loadings applied to the DSC that would cause instability are based on conservative rigid range seismic acceleration inputs to the HSM-HB of 0.43g horizontal in both transverse and longitudinal directions, and 0.20g vertical (Reference 13.10, Section 7.5). The stability analysis is based on showing that the overturning moment of the DSC on the HSM-HB support structure is smaller than the restoring force moment due to gravity. The non-rigid body modes of the DSC do not contribute to overturning so that the use of the rigid body accelerations is appropriate.

The resultant horizontal acceleration used to calculate the overturning moment is 0.43g. The vertical acceleration used to calculate the minimum restoring force is gravity less the vertical acceleration. The restoring moment is determined greater than the overturning moment CALVERT CLIFFS ISFSI USAR 13.8-14 Rev. 26

(Reference 13.10, Section 5.9). Therefore, the DSC canister is stable during a seismic accident.

B. Modular Constructed HSM-HB Seismic Analysis

1. HSM-HB Seismic Stress Analysis The resulting forces and moments in the HSM are found to be within the ultimate capacity (Reference 13.10).

2. HSM-HB Seismic Stability Evaluation In order to determine that the HSM-HB satisfies the overturning and sliding criteria provided in Reference 13.60, Table 10-4 the stability of the HSM-HB and the DSC inside the HSM-HB (which includes overturning and sliding) subjected to different accident loads is evaluated (Reference 13.10).

The structural evaluation of the HSM-HB performed in this calculation demonstrates that the design of the HSM-HB concrete components, DSC support structure, the shield door, the miscellaneous components, embedments, and the welds is adequate for all normal, off-normal, and accident loads considered. Also, a free standing HSM-HB with the end shield walls is stable against overturning and sliding when subjected to the design basis seismic, tornado wind, tornado missile, flood and blast load.

However, to satisfy the minimum factor of safety of 1.1 requirements (for stability) a minimum of two modules in a row of HSM-HB are required.

C. DSC Support Assembly Seismic Analysis An evaluation was performed for the DSC resting on the support rails inside the HSM-HB which includes the stability of the DSC against lifting off from one of the rails during a seismic event and potential sliding off of the DSC from the support rails. Conservatively, this evaluation was performed only for a DSC with minimum weight.

Because the stabilizing moment is greater than the overturning moment the DSC will not uplift from the support structure rails inside the HSM-HB (Reference 13.10, Section 5.9, Reference 13.2, Section 6.3 and Section 8.4.4).

CALVERT CLIFFS ISFSI USAR 13.8-15 Rev. 26

D. Transfer Cask Seismic Analysis Seismic stresses for the transfer cask with a NUHOMS-32PHB DSC are determined by conservatively scaling the seismic analysis results of the transfer cask (Reference 13.13, Section 5.1.4).

Seismic stability of the transfer cask is not a function of the DSC weight; and therefore, remains unaffected by the use of the NUHOMS-32PHB DSC.

13.8.2.3.3 Accident Dose Consequences Major components of the CCNPP ISFSI have been designed and evaluated to withstand the forces generated by the Design Basis Earthquake. Hence, there are no dose consequences.

13.8.2.4 Flood As discussed in USAR Section 3.2.2, flood loads are not applicable to the CCNPP ISFSI.

13.8.2.5 Transfer Cask Drop This section addresses the structural integrity of the transfer cask in the forced-cooling configuration, the NUHOMS-32PHB DSC, and its internals under a postulated transfer cask accident condition. The transfer trailer is not used for the transfer of the NUHOMS-32PHB DSC, only the self-propelled modular transporter with its associated transfer cask support skid is used to transfer the NUHOMS-32PHB DSC into a HSM-HB.

13.8.2.5.1 Cause of Accident As discussed in Reference 13.42, Section 6.0 an actual drop event is not considered to be credible. However, it is postulated that the transfer cask with the DSC inside will be subjected to an end, side, or oblique drop with a maximum height of 80 onto a thick concrete slab. A drop of greater than 80 is not considered because (a) transfer inside the Auxiliary Building will be performed using a single-failure-proof crane and (b) the self-propelled modular transporter and haul road are designed such that the transfer cask cannot be raised greater than 80 from the ground (Reference 13.11).

A failure of the self-propelled modular transporter will cause the braking system to fail-safe, that is "lock tight." The self-propelled modular transporter has emergency stop switches at easy access locations on all four sides of the transporter.

13.8.2.5.2 Accident Analysis The drop height (80), drop orientations, the properties of the target concrete surface, and the methodology used for the evaluation of the transfer with the NUHOMS-32PHB DSC as payload are described in Reference 13.11, Section 4.

CALVERT CLIFFS ISFSI USAR 13.8-16 Rev. 26

The design basis cask drop decelerations are specified in USAR Table 13.3-5.

NUHOMS-32PHB DSC Four accidental drop orientations are postulated for analysis.

A. Top end vertical drop B. Bottom end vertical drop C. Horizontal side drop D. Corner Drop As described in Reference 13.6, the sealed DSC weight and the basket + fuel weight analyzed are the same for both NUHOMS-32PHB DSC and NUHOMS-32P DSC. Therefore, drop load results from NUHOMS-32P are used directly for NUHOMS-32PHB design.

Information contained in USAR Section 12.8.2.5.2 NUHOMS-32P DSC is applicable to the NUHOMS-32PHB DSC.

Summary of Results The maximum membrane plus bending stress enveloping all the cask drop scenarios evaluated above are below the Level D allowable stresses for the NUHOMS-32PHB DSC during a cask drop accident (Reference 13.6).

NUHOMS-32PHB DSC Basket Assembly A. Horizontal Side Drop The basket and canister are analyzed for two modes of side drops. Firstly, the cask is assumed to drop away from the transfer support rails. Under this condition, 0, 45, and 60orientation of side drops are evaluated to bound the possible maximum stress cases. Secondly, the side drop occurs on transfer cask support rails at 180orientation.

The load resulting from the fuel assembly weight, for 1g and 75g accelerations, is applied as equivalent pressure on the plates. At 0and 180orientations, the pressure acts only on the horizontal plates while at other orientations, it is divided in components to act on both horizontal and vertical plates of the basket.

A nonlinear static stress analysis of the DSC basket structural assembly is conducted for computing the stresses for the 0, 45, 60, and 180drop orientations. A three-dimensional ANSYS model was used for this evaluation.

The maximum load of 75g was applied in each analysis.

Details of the analysis are described in Reference 13.7.

CALVERT CLIFFS ISFSI USAR 13.8-17 Rev. 26

Buckling is analyzed using a nonlinear finite element analysis of the basket by applying load at the 0 30, and 45 orientations relative to the basket plates. A maximum load of 100g was applied in each analysis and automatic time stepping was initiated allowing the program to determine the actual size of the load substep for a converged solution. The last converged solution represents the buckling load. In all orientations analyzed, the buckling load exceeded the USAR defined minimum applied load of 75g. Details of the analysis are described in Reference 13.7.

B. Vertical End Drop During an end drop, the fuel assemblies and fuel compartments are forced against the bottom of the cask.

For any vertical or near vertical loading, the fuel assemblies react directly against the bottom or top end of the cask and not through the basket structure as in lateral loading. It is only the dead weight of the basket that causes axial compressive stress during an end drop. Axial compressive stresses are conservatively computed by assuming that all load acts on the fuel compartment tubes during an end drop.

Details of the analysis are described in Reference 13.7 Summary of Results The enveloping maximum membrane plus bending stresses in the basket assembly structural components are below the ASME Code Level D allowable stresses for the NUHOMS-32P DSC basket assembly during a transfer cask drop accident.

Transfer Cask Forced-Cooling Configuration The CCNPP forced cooling transfer cask constitutes a minor modification of the original design of CCNPP transfer cask.

The design modification consists of the new top cover plate design with vent openings around the plate periphery that vent out forced air that is injected at the bottom of the cask, and of the added spacer disk with wedge shaped protrusions mounted to the bottom cover plate to facilitate air flow coming through ram access opening to the annular space around the DSC.

Reference 13.14 documents results of CCNPP forced cooling on-site transfer cask stress evaluation for the design accident scenarios: 75g side drop and 75g top end drops. These two accident scenarios are deemed the most appropriate accident scenarios to conservatively assess modified stress magnitudes and patterns due to the new design of top cover plate.

The bottom end drop condition calculated for NUHOMS-32P as described in Chapter 12 was based on a total package weight bounding the applicable weights of the modified transfer CALVERT CLIFFS ISFSI USAR 13.8-18 Rev. 26

cask with NUHOMS-32PHB. Therefore, results from NUHOMS -32P bottom end accident drop is bounding for NUHOMS-32PHB.

No evaluation is required for the corner drop since the stresses are bounded by the vertical drop stresses (Reference 13.2, Section 9.2.6).

The modified transfer cask is analyzed for 80 drop height accident using a 3D finite element analysis model designed to represent 180-degree part of cask structure with symmetrical boundary conditions.

The model represents NUHOMS-32PHB cask by ten structural components: structural shell, inner shell, top cover plate, top flange, bottom support ring, bottom cover plate, ram access ring, bottom end plate, lead shielding, and NS-3 bottom neutron shield.

The internal loading of the DSC was represented as pressure loadings applied to the transfer cask inner surfaces.

Supplementary boundary conditions refer to specific load case scenario. In the case of 75g side drop cask structural shell is fixed for a small arc 15° (180-degree model) in circumferential direction to simulate semi-rigid impact conditions and minimal boundary conditions in z direction are applied to avoid rigid body motion of model. Boundary conditions for side drop case are illustrated in Reference 13.14, Figure 9.

In case of 75g top end drop analyses, the cask model is fixed minimally in lateral direction to avoid rigid body motion of model, while contact with impact surface is simulated by means surface contact elements with fixed rigid impact target plane.

The CCNPP forced cooling on-site transfer cask is designed to meet the criteria of ASME Code Subsection NC for Class 2 components.

The acceptability of the design for Service Level D conditions is assessed by stress criteria stated in Reference 13.2. The criteria are based on Appendix F, Section F-1341.2 (Plastic Analysis) of ASME code, or Appendix F, Section F-1341.3 (Limit Analysis Collapse Load). For accident conditions (Service Level D), the ASME code criteria are intended to affirm structural integrity of the design but to allow for the loss of operability of components during or after postulated accident.

In particular, the bearing stresses need not to be evaluated except for pinned or bolted joints.

Qualification sections comprise of all sections of the packaging structure that potentially can contribute to design collapse or CALVERT CLIFFS ISFSI USAR 13.8-19 Rev. 26

excessive plastic deformation of the structure. For each component, ASME code stress classification is conducted for all shell and plate sections, and for all significant stress paths of more complicated geometrical shapes.

The calculation in Reference 13.14 has been construed to validate the design of NUHOMS-32PHB cask for the accident condition 75g side drop and 75g end drop scenarios. The detailed results and stress qualification discussion is documented in Reference 13.14, Section 8.3. The calculation shows that new design version of top cover plate, allowing for vent openings, satisfies ASME code criteria for the analyzed events.

The structural evaluation of the intact fuel assembly design basis drops is performed to demonstrate that sub-criticality is maintained and fuel cladding remains intact following the design basis drops.

An equivalent static finite element analysis was performed for side drop evaluation. It was assumed that the cladding is subjected to lateral loads comprised of both the fuel and cladding weights but no credit is taken for stiffness of the fuel pellets. A maximum normal operating temperature of 750F was conservatively used. A side drop acceleration of 75g was considered for the fuel assemblies. It was demonstrated that the maximum calculated bending stress plus rod internal pressure stress is significantly lower than the yield strength of the fuel cladding material.

Therefore, it was concluded that the fuel cladding will not fail under hypothetical side drop accident condition.

It is concluded that the analyses for NUHOMS-32P+ DSC in Reference 13.61 bound all the fuel assemblies in the NUHOMS-32PHB DSC except for the AREVA fuel assemblies. Since the geometry for the AREVA fuel assembly is the same as the one used in the NUHOMS-32P+ DSC analysis, the results were scaled due to the differences in the M5 and Zircaloy-4 materials. The evaluation concluded that the fuel cladding deforms elastically with very small amount of maximum principal strain. Therefore, the fuel cladding maintains its structural integrity during the hypothetical end drop condition.

13.8.2.5.3 Accident Dose Consequences Dose calculations for the transfer cask drop accident with a NUHOMS-32PHB DSC use the same methodology and model as the calculations for the NUHOMS-24P DSC, and continue to assume that the neutron shielding is lost. The doses for the NUHOMS-32PHB DSC, with the increased CALVERT CLIFFS ISFSI USAR 13.8-20 Rev. 26

neutron source term, are 3521 mrem/hr on contact, and 152.2 mrem/hr at 15 (Reference 13.30, Tables 13-2 and 13-4). The contact dose rate remains below the limit of 5 rem/hr for this accident. The recovery dose to an on-site worker, at an average distance of 15, increases from 1164 mrem for a NUHOMS-32P DSC to 1218 mrem during the 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> time required to mitigate the accident. The recovery dose remains below the limit of 5 rem at the site boundary since the total dose at 15 is much less than 5 rem.

13.8.2.6 Lightning The modular constructed HSM-HBs are equipped with a lightning protection system. Thus, the lightning evaluation presented in USAR Section 8.2.6 for a poured in place HSMs is applicable for the modular constructed HSM-HBs and the NUHOMS-32PHB DSC System.

13.8.2.7 Blockage of Air Inlets and Outlets This accident is postulated to consist of the complete and total blockage of all HSM-HB air inlets and outlets for a period of 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.

13.8.2.7.1 Cause of Accident See USAR Section 8.2.7.1.

13.8.2.7.2 Accident Analysis The stresses caused by the additional weight of debris blocking the air inlets and outlets are bounded by the structural consequences of other accidents described in this section (i.e., tornado and earthquake analyses). The thermal consequences of this accident result from heating of the DSC and HSM-HB due to the loss of natural convection cooling.

The thermal analyses to determine the temperature rise for the HSM-HB and DSC components due to blocked vents are performed using the ANSYS finite element methodology (Reference 13.44 and Reference 13.23, Section 5.1.2). The design basis pressure is considered in the DSC accident pressure evaluation presented in USAR Section 13.8.2.9.

The thermally induced stresses for the HSM for the blocked vent case are calculated using an ANSYS finite element model.

The same methodology was used for evaluation of the 61BTH DSC in the HSM-H under Transnuclear general license approved by the NRC. A maximum decay heat of 31.2 kW was considered for the 61BTH as opposed to 29.6 kW for the NUHOMS-32PHB. The thermally induced stresses for the DSC during accident conditions are addressed in Reference 13.23.

CALVERT CLIFFS ISFSI USAR 13.8-21 Rev. 27

13.8.2.7.3 Accident Dose Consequences To assure that the HSM concrete design temperature is not exceeded, the HSM vents are required to be inspected at 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> intervals (see Technical Specifications Surveillance Requirement 4.4.1.2) to verify that they are open, and to clear any blockage found within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> of discovery. Title 10 CFR 72.106 establishes an accident dose limit of 5 rem at the site boundary. There is no radiological release from this accident.

Direct doses from blockage of air inlets and outlets for the current HSM design is highest for the NUHOMS-24P DSC design, which has a dose rate of 73 mrem/hr at the air inlet vent. Doses to an on-site worker performing a recovery action are 584 mrem (73 mrem/hr x 8 hr) during an estimated 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> debris removal period. The highest vent dose rate for the NUHOMS-32PHB DSC stored in the HSM-HB is 121 mrem/hr at the front inlet (Reference 13.31, Table 8-1), not including credit for additional gamma shielding provided by the alternate bird screen design. This would increase the on-site worker 8-hour debris removal dose to 968 mrem (121 mrem/hr x 8 hr).

13.8.2.8 Dry Shielded Canister Leakage Calvert Cliffs ISFSI USAR Sections 8.2.8 and 12.8.2.8 evaluate a non-mechanistic release to the environment of the gap inventory of Kr-85 fission gas from all fuel contained in the NUHOMS-24P and NUHOMS-32P DSCs, respectively. Current NRC guidance on analysis methodology for this accident is specified in ISG-5 Revision 1, Confinement Evaluation.

Section IV.3 of ISG-5, Revision 1 also offers the option of testing closure welds to be leak tight, as defined in American National Standard for Leakage Tests on Packages for Shipment of Radioactive Materials, ANSI N14.5-1997, in lieu of performing a DSC leakage dose analysis. The ANSI N14.5-1997 defines leak tight as a degree of package containment that in a practical sense precludes any significant release of radioactive materials, and is achieved by demonstration of a leakage rate less than or equal to 1x10-7 ref*cc/s, of air at an upstream pressure of 1 atmosphere (atm) absolute (abs) and a downstream pressure of 0.01 atmabs or less. Technical Specification Limiting Condition for Operation 3.2.2.2 and Surveillance Requirement 4.2.2.1 implements the requirements to ensure the NUHOMS-32PHB DSC closure welds will be leak tight. Furthermore, stress analyses of the NUHOMS-32PHB DSC demonstrate that the pressure boundary is not breached by any design basis event since it meets the applicable stress limits for normal, off-normal, and postulated accident conditions. Therefore, the DSC leakage analysis is not required and was not performed for the NUHOMS-32PHB DSC.

13.8.2.9 Accidental Pressurization of Dry Shielded Canister This accident addresses the consequences of accidental pressurization of the NUHOMS-32PHB DSC.

13.8.2.9.1 Cause of Accident See USAR Section 8.2.9.1.

CALVERT CLIFFS ISFSI USAR 13.8-22 Rev. 27

13.8.2.9.2 Accident Analysis The maximum NUHOMS-32PHB DSC pressurization is calculated assuming that 100% of the fuel rods in a DSC rupture and release the fission and fuel rod fill gasses to the DSC cavity. The fuel rod fission gas release fraction is assumed to be 30% and the fuel rod fill gas release fraction is assumed to be 100%. The maximum fuel rod fill gas pressure is assumed to be 1400 psia (Reference 13.9) and is used to calculate the quantity of fill gas released from fuel rods to the DSC cavity during fuel rod rupture conditions. The internal DSC pressure is calculated at the maximum ambient temperature of 104°F (Reference 13.2, Table 8-10) and a solar heat flux of 127.0 Btu/hr-ft2.

The limiting accident for DSC pressurization is the transfer fire accident as discussed in Reference 13.24 and 13.22. Under this condition, the gas temperature in the DSC will rise to 732°F with a DSC internal pressure of 91.4 psig (Reference 13.24).

The analysis of accidental pressurization of the DSC includes the effect of fuel burnup on internal fuel rod pressure by using the volume of fission gas generated in the fuel rod at the maximum burnup of 62,000 MWD/MTU. The results of the analysis show that the maximum DSC accident pressures are within the allowable design bases limits.

13.8.2.9.3 Accident Dose Calculations Since the maximum NUHOMS-32PHB DSC accident pressure is within the design basis limits, there are no dose consequences.

13.8.2.10 Forest Fire This postulated event involves a forest fire occurring in the woods adjacent to the CCNPP ISFSI.

13.8.2.10.1 Cause of Accident See USAR Section 8.2.10.1.

13.8.2.10.2 Accident Analysis The ISFSI USAR Sections 8.2.10 and 12.8.2.10 postulates a forest fire occurring in the woods adjacent to the CCNPP ISFSI.

The initial parameters used in those sections remain unchanged for the NUHOMS-32PHB DSC in the HSM-HB.

The damage to the HSM-HB wall, based on the wall temperature gradient resulting from the fire (depth at which temperatures remain below 350°F) will be limited to a thickness of 9 (Reference 13.40). Fuel cladding temperature limits will be maintained within the fuel cladding short-term temperature CALVERT CLIFFS ISFSI USAR 13.8-23 Rev. 26

limit, and the NUHOMS-32PHB DSC internal pressure limit (100 psig) will not be exceeded. The effect of the surface cracking and spalling will be minimal with respect to the load capacity of the HSM-HB walls, but will reduce the effective shielding thickness and increase dose rates outside of the HSM-HB. The HSM storing fuel-loaded NUHOMS-24P and/or NUHOMS-32P DSCs surface dose rate increase associated with forest fire induced spalling of the HSM wall was based on a 12 reduction in concrete thickness producing a factor of 20 increase in dose rate at the HSM surface (Reference 13.46).

For the NUHOMS-32PHB DSC, a 9 reduction in concrete depth would translate to surface dose rates increasing by a factor of 9.5 using the same rule. The original design goal for the CCNPP ISFSI was that the spalling not increase dose rates to a level beyond which repair actions could be performed by conventional methods (1 rem/hr at 1m). For the NUHOMS-32PHB DSC, forest fire spalling would result in a dose rate of 59.3 mrem/hr at the HSM-HB surface (9.5 x 6.27 mrem/hr from 13.31, Table 8-1) which is still significantly below the 1 rem/hr design goal for spalling repair. Thus, it can be concluded that the NUHOMS-32PHB DSC would also not adversely impact the ability to repair spalled concrete following a forest fire. Actions to mitigate the fire and repair the HSM-HBs will ensure that off-site dose consequences will be limited and of short duration and will remain within the limits of 10 CFR 72.106.

13.8.2.10.3 Accident Dose Consequences There are no accident dose consequences associated with the postulated forest fire accident.

13.8.2.11 Liquefied Natural Gas Plant or Pipeline Spill or Explosion Discussion in USAR Section 8.2.11 is applicable to the modular constructed HSM-HB and NUHOMS-32PHB DSC system.

A more recent evaluation of the expanded Liquified Natural Gas plant was performed by the Maryland Department of Natural Resources (the 2006 PPRP Study) and was submitted to the NRC by CCNPP for Units 1&2 and the ISFSI on February 20, 2008. In addition, in response to request for additional information questions on CCNPP3, Unistar submitted additional analyses of the hazards associated with Liquified Natural Gas pipeline on November 11, 2008 (ADAMS Accession No. ML083180126). Based on the combination of the two analyses, the NRC issued a Safety Evaluation Report on October 28, 2009 indicating that the likelihood of exceeding 1 psi overpressures at the CCNPP (considered the NRC minimum threshold for structural damage due to explosion), associated with two scenarios identified in the 1993 A.D. Little study (i.e., tanker approach collisions and loading dock Liquified Natural Gas releases) meets the acceptance criterion of about 10-6 per year. The increase in the storage tank size from 600,000 to 1,000,000 barrels was found to be acceptable in that the estimated overpressure at the CCNPP was still less than 1 psi.

CALVERT CLIFFS ISFSI USAR 13.8-24 Rev. 26

13.8.2.12 Load Combinations The load categories associated with normal, off-normal, and accident conditions have been described and analyzed in previous chapters.

Evaluation of the load combination for the NUHOMS-32PHB DSC important-to-safety components is addressed in this section.

The methodology used in combining normal, off-normal, and accident loads and their associated overload factors for various NUHOMS-32PHB DSC components is presented in Reference 13.6, Table 5-1. The load combination analysis results showed that the calculated stresses are less than the code allowable limits for various load combinations shown in Tables 13.8-1, 13.8-2, 13.8-3, 13.8-4, 8.2-14, 8.2-15, and 8.2-16.

When compared to the NUHOMS-24P DSC, the confinement boundary stress allowable limits (Table 13.8-3) have been altered to an elastic/plastic analysis for all accident conditions except for the 100 psig applied to the inner pressure boundary combinations (D3, D4, & D5).

Horizontal storage module enveloping load combination results were obtained based on a conservative interpretation of the CCNPP calculation.

The forces and moments, including thermal loads, are taken from the ANSYS output presented in Reference 13.10, Section 7-2.

The load combination analysis results show that the calculated stresses are less than the code allowable stresses for all the specified normal, off-normal, and accident condition load combinations.

13.8.2.13 Other Event Considerations Use of the NUHOMS-32PHB DSC design does not change the analysis described in USAR Section 8.2.13.

13.8.3 SITE CHARACTERISTICS AFFECTING SAFETY ANALYSIS All site characteristics affecting safety analyses presented in this document are noted where they apply.

CALVERT CLIFFS ISFSI USAR 13.8-25 Rev. 26

TABLE 13.8-1 NUHOMS-32PHB DRY SHIELDED CANISTER ENVELOPING LOAD COMBINATION RESULTS FOR NORMAL AND OFF-NORMAL LOADS (ASME Service Levels A and B)

CONTROLLING(a)

LOAD ALLOWABLE(b)(c)

COMBINATION STRESS (ksi)

DSC COMPONENTS STRESS TYPE A4/B3/B5 A4/B3/B5 DSC Shell Primary Membrane B3 18 Membrane + Bending A4 27 Primary + Secondary A4 53.9 Bottom Cover Plate Primary Membrane B5 19 Membrane + Bending B3 28.4 Primary + Secondary B3 56.9 Top Pressure Plate Primary Membrane B5 19 (top inner plate)

Membrane + Bending B5 28.4 Primary + Secondary B5 56.9 Top Structural Plate Primary Membrane B5 19 (top outer plate)

Membrane + Bending B5 28.4 Primary + Secondary B5 56.9 (a) See USAR Table 13.3-6 for load combination nomenclature (Reference 13.6).

(b) See Reference 13.6, Tables 7-3, 7-4, and 7-5 for allowable stress criteria. Material properties were obtained from Reference 13.6, Tables 5-2 and 5-3 at a design temperature.

(c) Allowable limits are for stainless steel material at 595°F.

NOTE: Refer to Reference 13.6, Table 5-1 for Bounding Load Combinations A, B, C, and D.

CALVERT CLIFFS ISFSI USAR 13.8-26 Rev. 26

TABLE 13.8-2 NUHOMS-32PHB DRY SHIELDED CANISTER ENVELOPING LOAD COMBINATION RESULTS FOR ACCIDENT LOADS (ASME Service Level C)

CONTROLLING(a)

LOAD ALLOWABLE(b)(c)

DSC COMPONENTS STRESS TYPE COMBINATION STRESS (ksi)

Primary Membrane C1 21.6 DSC Shell Membrane + Bending C1 32.4 Primary Membrane C1 21.6 Bottom Cover Plate Membrane + Bending C6 32.4 Top Pressure Primary Membrane C1 21.6 Plate(inner) Membrane + Bending C1 32.4 Top Structural Plate Primary Membrane C1 21.6 (outer) Membrane + Bending C1 32.4 (a) See USAR Table 13.3-6 for load combination nomenclature.

(b) See Reference 13.6, Tables 12-2 and 7-6 for allowable stress criteria. Material properties were obtained from Reference 13.6, Table 5-5 at a design temperature.

(c) Allowable limits are for stainless steel material at 460°F.

CALVERT CLIFFS ISFSI USAR 13.8-27 Rev. 26

TABLE 13.8-3 NUHOMS-32PHB DRY SHIELDED CANISTER ENVELOPING LOAD COMBINATION RESULTS FOR ACCIDENT LOADS (ASME Service Level D)(c)

CONTROLLING(a) ELASTIC LOAD ALLOWABLE(b)

DSC COMPONENTS STRESS TYPE COMBINATION STRESS (ksi)

Primary Membrane D2 39.6 DSC Shell Membrane + Bending D2 59.4 Primary Membrane D2 44.38 Bottom Cover Plate Membrane + Bending D3 63.4 Primary Membrane D2 44.38 Top Pressure Plate Membrane + Bending D2 63.4 Primary Membrane D2 44.38 Top Structural Plate Membrane + Bending D2 63.4 Primary Membrane D2 44.4 Basket Assembly Membrane + Bending D2 57.1 Top End Structural Primary -- 21.6 Weld Bottom End Structural Primary -- 45.1 Weld For more information see Reference 13.6.

(a) See USAR Table 13.3-6 for load combination nomenclature.

(b) See Reference 13.6, Tables 12-2 and 7-6 for allowable stress criteria. Material properties were obtained from Reference 13.6, Table 5-2 at a design temperature.

(c) Allowable limits are for stainless steel material at 460°F for normal conditions and 595°F for accident conditions (storage).

(d) Used on 100 psi pressure applied at outer boundary case.

CALVERT CLIFFS ISFSI USAR 13.8-28 Rev. 26

TABLE 13.8-4 NUHOMS-32PHB DRY SHIELDED CANISTER SUPPORT ASSEMBLY ENVELOPING LOAD COMBINATION RESULTS Rail Component Results Shear Stress Stiffener Plate Load Comb.(1) Interaction Ratio Ratio Stress Ratio C1S 0.35 0.67 0.19 C2S 0.58 0.84 0.00 C3S 0.58 0.93 0.22 C4S 0.51 0.96 0.18 C5S 0.40 0.63 0.55 Extension Plates and Cross Member Results Extension Plate Cross Members Load Comb.(1)

Interaction Ratio Stress Ratio C1S 0.77 0.25 C2S 0.77 0.32 C3S 0.71 0.21 C4S 0.60 0.25 C5S 0.71 0.33 (1) Load combination are as defined in Reference 13.10.

Notes:

Interaction ratio are for reference only. Allowable loads are per Reference 13.10.

CALVERT CLIFFS ISFSI USAR 13.8-29 Rev. 26

13.9 CONDUCT OF OPERATIONS The CCNPP ISFSI is operated under the same corporate management organization responsible for operation of the CCNPP. The conduct of operations for the CCNPP ISFSI is described in Chapter 9.0. The discussion presented in Chapter 9.0 is not affected by the addition of the NUHOMS-32PHB DSC to the NUHOMS System.

CALVERT CLIFFS ISFSI USAR 13.9-1 Rev. 26

13.10 OPERATING CONTROLS AND LIMITS The discussion presented in Chapter 10 is applicable to the CCNPP ISFSI NUHOMS-32PHB DSC, the HSM-HB, the self-propelled modular transporter, the hydraulic ram and transfer cask support skid used with the self-propelled modular transporter and the transfer cask in the forced-cooling configuration.

CALVERT CLIFFS ISFSI USAR 13.10-1 Rev. 26

13.11 QUALITY ASSURANCE The quality assurance program for the CCNPP ISFSI covers the construction phase, the operational phase, and the decommissioning phase of structures, systems, and components of the CCNPP ISFSI which are important-to-safety. The CCNPP ISFSI quality assurance program is discussed in Chapter 11. The discussion presented in Chapter 11 is applicable to the CCNPP ISFSI NUHOMS-32PHB DSC, the modular constructed HSM-HB, the self-propelled modular transporter, the hydraulic ram and transfer cask support skid used with self-propelled modular transporter and the transfer cask in the forced-cooling configuration.

CALVERT CLIFFS ISFSI USAR 13.11-1 Rev. 26

13.12 NOT USED CALVERT CLIFFS ISFSI USAR 13.12-1 Rev. 26

13.13 REFERENCES 13.1 CCNPP Calculation No. CA07255, S&L Calculation No. 11562-019-RAD-01, Calvert Cliffs ISFSI Radiological Source Term for the NUHOMS-32PHB DSC Design Calculation 13.2 CCNPP Calculation No. CA07299, Transnuclear Calculation No. NUH32PHB-0101, Design Criteria Document (DCD) for NUHOMS 32PHB System for Storage Design Calculation 13.3 CCNPP Calculation No. CA07300, Transnuclear Calculation No. NUH32PHB-0201, NUHOMS 32PHB Weight Calculation of DSC/TC System Design Calculation 13.4 CCNPP Calculation No. CA07301, Transnuclear Calculation No. NUH32PHB-0202, Evaluation of the 32PHB System for Hydrogen Generation Effects Design Calculation 13.5 CCNPP Calculation No. CA07302, Transnuclear Calculation No. NUH32PHB-0203, PWR Fuel Rod Drop Accident Side Drop Loading Stress Analysis for NUHOMS 32PHB System Design Calculation 13.6 CCNPP Calculation No. CA07303, Transnuclear Calculation No. NUH32PHB-0204, NUHOMS 32PHB Canister Structural Evaluation for Storage and Onsite Transfer Loads Design Calculation 13.7 CCNPP Calculation No. CA07304, Transnuclear Calculation No. NUH32PHB-0205, NUHOMS 32PHB Basket Evaluation for Storage and Transfer Loads Design Calculation 13.8 CCNPP Calculation No. CA07305, Transnuclear Calculation No. NUH32PHB-0206, NUHOMS 32PHB Transfer Cask - Local Shell Stresses at Trunnion Locations Design Calculation 13.9 CCNPP Calculation No. CA07306, Transnuclear Calculation No. NUH32PHB-0207, Fuel Rod End Drop Analysis for NUH32PHB using LS-DYNA Design Calculation 13.10 CCNPP Calculation No. CA07307, Transnuclear Calculation No. NUH32PHB-0208, HSM-HB Structural Analysis for NUHOMS 32PHB System Design Calculation 13.11 CCNPP Calculation No. CA07308, Transnuclear Calculation No. NUH32PHB-0209, CCNPP-FC Transfer Cask Impact onto the Concrete Pad, LS-DYNA Analysis (80 Inch Side, Corner, and End Drops) 13.12 CCNPP Calculation No. CA07309, Transnuclear Calculation No. NUH32PHB-0210, NUHOMS 32PHB Canister, Basket and Fuel Assemblies Dynamic Load Factors Design Calculation 13.13 CCNPP Calculation No. CA07310, Transnuclear Calculation No. NUH32PHB-0211, Reconciliation for Transfer Cask CCNPP-FC Structural Evaluation for 32PHB Design Calculation 13.14 CCNPP Calculation No. CA07311, Transnuclear Calculation No. NUH32PHB-0212, CCNPP-FC Transfer Cask Structural Evaluation - Accident Conditions, 75G Side Drop and 75G Top End Drop Cases 13.15 CCNPP Calculation No. CA07312, Transnuclear Calculation No. NUH32PHB-0213, Lifting Lug Structural Evaluation for 32PHB Design Calculation 13.16 CCNPP Calculation No. CA07313, Transnuclear Calculation No. NUH32PHB-0214, NUHOMS 32PHB Reconciliation of Civil Structures Design Calculation 13.17 CCNPP Calculation No. CA07314, Transnuclear Calculation No. NUH32PHB-0216, NUHOMS 32PHB Reconciliation for Lift Beam Design Calculation CALVERT CLIFFS ISFSI USAR 13.13-1 Rev. 26

13.18 CCNPP Calculation No. CA07315, Transnuclear Calculation No. NUH32PHB-0217, NUH32PHB DSC Stress Analysis Due to Blow Down and Test Pressure Design Calculation 13.19 CCNPP Calculation No. CA07316, Transnuclear Calculation No. NUH32PHB-0218, NUHOMS 32PHB Cask Spacer Disc Friction Screw Attachment Evaluation Design Calculation 13.20 CCNPP Calculation No. CA07317, Transnuclear Calculation No. NUH32PHB-0400, Benchmarking of ANSYS Model of the OS200FC Transfer Cask 13.21 CCNPP Calculation No. CA07318, Transnuclear Calculation No. NUH32PHB-0401, Thermal Evaluation of NUHOMS 32PHB Transfer Cask for Normal, Off Normal and Accident Conditions with Forced Cooling (Steady State) Design Calculation 13.22 CCNPP Calculation No. CA07319, Transnuclear Calculation No. NUH32PHB-0402, Thermal Evaluation-NUHOMS 32PHB Transfer Cask for Normal, Off Normal and Accident Conditions Design Calculation 13.23 CCNPP Calculation No. CA07320, Transnuclear Calculation No. NUH32PHB-0403, Thermal Evaluation for NUHOMS 32PHB Canister for Storage and Transfer Conditions Design Calculation 13.24 CCNPP Calculation No. CA07321, Transnuclear Calculation No. NUH32PHB-0404, Internal Pressure for NUHOMS 32PHB DSC for Storage and Transfer Conditions Design Calculation 13.25 CCNPP Calculation No. CA07322, Transnuclear Calculation No. NUH32PHB-0405, Thermal Expansion of NUHOMS 32PHB System for Transfer and Storage Conditions Design Calculation 13.26 CCNPP Calculation No. CA07323, Transnuclear Calculation No. NUH32PHB-0406, Thermal Evaluation-NUHOMS 32PHB Transfer Cask for Normal, Off-Normal and Accident Conditions (Heat Load <29.6KW) Design Calculation 13.27 CCNPP Calculation No. CA07324, Transnuclear Calculation No. NUH32PHB-0407, Effective Thermal Properties of Bounding CE 14X14 Fuel Assembly for 32PHB DSC Design Calculation 13.28 CCNPP Calculation No. CA07325, Transnuclear Calculation No. NUH32PHB-0408, Thermal Analysis of NUHOMS 32PHB DSC for Vacuum Drying Operations Design 13.29 CCNPP Calculation No. CA07328, Transnuclear Calculation No. NUH32PHB-0501, Source Terms and Material Densities for Shielding Evaluation of NUHOMS 32PHB System Design Calculation 13.30 CCNPP Calculation No. CA07329, Transnuclear Calculation No. NUH32PHB-0502, Calvert Cliffs NUHOMS 32PHB Radiation Dose Rates for Loading and Transfer Design Calculation 13.31 CCNPP Calculation No. CA07330, Transnuclear Calculation No. NUH32PHB-0503, HSM-H Shielding Analysis for 32PHB System Design Calculation 13.32 CCNPP Calculation No. CA07332, Transnuclear Calculation No. NUH32PHB-0505, Site Dose Analysis for NUHOMS 32PHB System Design Calculation 13.33 CCNPP Calculation No. CA07333, Transnuclear Calculation No. NUH32PHB-0600, Criticality Evaluation for NUHOMS 32PHB System Design Calculation CALVERT CLIFFS ISFSI USAR 13.13-2 Rev. 26

13.34 CCNPP Calculation No. CA07334, Transnuclear Calculation No. NUH32PHB-0603, Criticality Evaluation for NUHOMS 32PHB System Design Calculation 13.35 CCNPP Calculation No. CA07584, Cooling Time and Fit Equations for Spent Fuel to be Placed in NUHOMS-32PHB DSC 13.36 CCNPP Calculation No. CA07255, Transnuclear, Inc., Updated Final Safety Analysis Report for the Standardized NUHOMS Horizontal Modular Storage System for Irradiated Nuclear Fuel, NRC Docket No. 72-1004, Transnuclear Document No.

NUH-003, Revision 11 13.37 Transnuclear, Inc., Updated Final Safety Analysis Report for the NUHOMS HD Horizontal Modular Storage System for Irradiated Nuclear Fuel, NRC Docket No.

72-1030, Revision 2 13.38 ASME Boiler and Pressure Vessel Code,Section III, Division 1, Subsection NB and NC and Appendix F, 1998 Edition with 1999 Addenda 13.39 NRC, ISG-15, 2001, (Spent Fuel Project Office Interim Staff Guidance), Materials Evaluation 13.40 CCNPP Calculation No. CA07326, Transnuclear Calculation No. NUH32PHB-0409, Forest Fire Thermal Evaluation for CCNPP ISFSI 13.41 CCNPP Calculation CA07625, SPMT Stability Calculation Due to Overturning Wind Force 13.42 CCNPP Calculation No. CA07894, Transnuclear Calculation No. NUH32PHB-0111, Design Report for 32PHB DSC 13.43 CCNPP Drawing 84247, NUHOMS 32PHB ISFSI Onsite Transfer Cask Spacer Option for Forced Cooling 13.44 CCNPP Calculation No. CA07327, Transnuclear Calculation No. NUH32PHB-0410, Reconciliation of Thermal Analysis Results for 32PHB DSC Storage in HSM-HB Module Design Calculation 13.45 Topical Report for the NUTECH Modular Storage System (NUHOMS-24P) for Irradiated Nuclear Fuel, NUH-002, Revision 1A, July 1989 13.46 CCNPP Calculation CA03945, Revised Calvert Cliffs Forest Fire Analysis 13.47 CCNPP Calculation CA08096, Thermal Performance of 32P DSC Inside HSM-HB for Normal and Off-Normal Conditions 13.48 CCNPP Drawing 84236, (NUHOMS Dwg. NUH32PHB-30-1), NUHOMS 32PHB Canister for PWR Fuel Shell and Bottom Plug Assembly 13.49 CCNPP Drawing 84237, (NUHOMS Dwg. NUH32PHB-30-2), NUHOMS 32PHB Canister for PWR Fuel Shell and Bottom Plug Assembly 13.50 CCNPP Drawing 84238, (NUHOMS Dwg. NUH32PHB-30-3), NUHOMS 32PHB Canister for PWR Fuel Shell and Siphon Pipe Assembly Details 13.51 CCNPP Drawing 84239, (NUHOMS Dwg. NUH32PHB-30-4), NUHOMS 32PHB Canister for PWR Fuel Top Shield Plug Details 13.52 CCNPP Drawing 84240, (NUHOMS Dwg. NUH32PHB-30-5), NUHOMS 32PHB Canister for PWR Fuel Top Cover Plate and Siphon/Vent Port Covers 13.53 CCNPP Drawing 84241, (NUHOMS Dwg. NUH32PHB-30-6), NUHOMS 32PHB Basket Assembly CALVERT CLIFFS ISFSI USAR 13.13-3 Rev. 26

13.54 CCNPP Drawing 84242, (NUHOMS Dwg. NUH32PHB-30-7), NUHOMS 32PHB DSC Basket Details 13.55 CCNPP Drawing 84244, (NUHOMS Dwg. NUH32PHB-30-9), NUHOMS 32PHB Basket Plate Details 13.56 CCNPP Drawing 84243, (NUHOMS Dwg. NUH32PHB-30-8), NUHOMS 32PHB Basket Assembly Rails and Stud Details 13.57 CCNPP Drawing 84245, (NUHOMS Dwg. NUH32PHB-30-10), NUHOMS 32PHB Parts List 13.58 ISFSI Technical Specification Amendment No. 11 13.59 CCNPP Calculation CA07328, Transnuclear Calculation No. 10955-0501, Neutron Fluence and Gamma Exposure on 32PHB and HSM-HB Materials 13.60 Design Criteria Document (DCD) for the NUHOMS - 24PTH System for Transportation and Storage, Transnuclear Specification No. NUH24PTH.0101, Revision 0 13.61 CCNPP Calculation No. CA07295, Transnuclear Calculation No. NUH32PT-0204, Fuel End Drop Analysis for NUH32P+ using LS-DYNA CALVERT CLIFFS ISFSI USAR 13.13-4 Rev. 26