Thermal Stresses

Containment

• Determining accurate seismic loads and responses
• Providing accurate safety analyses to regulators
• Estimating hydrogen release hazards

• Avoid over-designing by performing accurate seismic analyses
• Accident simulation when 1-D tools are insufficient
  • Impact of accidents on structural integrity
  • Fracture mechanics
  • Emergency core cooling system behavior
  • Showing jet-strike survivability
  • Hydrogen dispersion within containment

Coolant Pumps

• Cavitation
• Installation effects not taken into account by original design
• Understanding performance in off-design (start-up and accident) conditions

• Understand the impact of installation effects before deployment
• Optimize performance by determining inlet and outlet flow angles and separation patterns
• Reduce the number of hardware prototypes needed in the pump design and installation process
• Allows parametric investigation of scale-up effects for these extremely large pumps, which is not possible through testing, but straightforward with simulation.

Reactor Pressure Vessels

• Safety analysis for complex stratified flow
• Code-checking for stress analysis in a timely fashion

• Supply regulators with thermal hydraulic predictions for a wide range of LOCA scenarios
• Stratification caused by thermal variations across cold legs
• Use a pressure vessel design tool with built-in code checks

Fuel Assemblies

• Designing for seismic safety without over-designing
• Optimizing for thermal transfer in operating and LOCA conditions
• Designing for flow-induced vibration
• Limiting cladding fretting and wear

• Reduce design time and physical prototypes through simulation
• Spring design
• Assembly seismic vibration analysis
• Mixing vane design
• Fluid-structure interaction simulation

Pressurizers

• Designing steam generation and spray cooling system for optimal responsiveness to pressure changes
• Design time for code checks

• Cost savings through virtual prototyping of new designs and troubleshooting for existing units
  • Heat transfer and phase change due to heating
  • Natural circulation
  • Spray distribution
  • Local condensation rates
• Rapid vessel design with built-in code checks

Steam Generators

• Tube vibration
• Accident analysis under natural convection conditions
• Design for optimal heat transfer

• Reduce expensive and time-consuming scaled test loop experiments
  • Investigate and optimize tube vibration sensitivity to flow conditions
  • Extend test results from experimental to full scale conditions
  • Confirm results from system level tools
  • Investigate installation effects

 Passive Safety Systems

• Inaccuracy of system-level tool safety analyses when natural circulation and mixing are fundamental to the process
• Scale-up of parametric relationships from lab to full size

• Gain physical insight about flow structures to guide safety system design
• Generate new parametric relationships to embed in system-level tools
• Extend behavior prediction from experimental to full scale conditions

Generation IV Reactors

• Modeling high temperature gaseous flows (sometimes involving chemical reactions) with codes designed for water and steam
• Modeling natural circulation and mixing in 1-D
• Scale-up of parametric relationships from lab to full size

• Model the full flow physics of gas-cooled reactors
• Gain physical insight about flow structures to guide safety system design
• Generate new parametric relationships to embed in system-level tools
• Extend behavior prediction from experimental to full scale conditions

Waste Storage and Handling

• Meeting regulatory requirements for repositories and transport and storage devices
  • Thermal management
  • Structural impacts

• Cost efficient design and troubleshooting of storage devices and repositories to comply with regulatory requirements
  • Structural integrity during container impact
  • Cooling efficiency from forced or natural convection and conduction
  • Pool fire thermal predictions