Argonne’s SAS4A/SASSYS-1 safety analysis code system is a simulation tool that can perform deterministic transient safety analysis of anticipated operational events, as well as design-basis and beyond-design-basis accidents for advanced nuclear reactors. The original code development was for sodium-cooled fast reactors, and sodium boiling can be modeled. However, basic core thermal-hydraulics and systems analysis features are applicable to other liquid-metal cooled reactor concepts.

Applications

• Safety analysis of fast reactors
• Simulations for operational, design-basis and beyond-design-basis events
• Passive heat removal and natural circulation flow predictions
• Severe accident modeling with sodium boiling, fuel melting and pin failure

Features

The current version (version 5) features:

• Detailed code manual
• Single-pin assembly models for rapid evaluation of transients
• Detailed thermal-hydraulic sub-channel models for subassembly pin bundles
• Support for three-dimensional visualization of sub-channel temperatures
• Support for liquid-metal coolants such as sodium, NaK, lead and LBE, as well as other single-phase coolants
• Full-plant coolant system models to simulate passive heat removal and natural shutdown
• Oxide fuel models for fuel melting, in-pin motion, pin failure, and ex-pin fuel dispersal and freezing
• Metal fuel models for fuel-clad eutectic formation and cladding failure
• High-fidelity decay heat models
• Built-in support for ANS standard decay heat properties
• Built-in support for alternative coolants in decay heat removal loops
• Support for line-based comments in input files
• Support for an unlimited number of time steps
• Support for coupling to third-party computational fluid dynamics tools (such as STAR-CCM+) for representing thermal stratification in large volumes
• Support for coupling to DIF3D-K for reactor spatial kinetics

Technical Details/Requirements

• Executable versions are available for Linux, Mac OS X and Windows
• Source code is compliant with Fortran 90/95 free-formatted source format and can be compiled on a variety of operating systems including Unix, Linux, Mac OS X and Windows. A standards-compliant Fortran compiler is required.