ISS is a Leading Provider

Comprehensive Nuclear Safety Analysis Solutions

State-of-the-art simulation and analysis software for thermal-hydraulic systems and reactor safety

Our Product Portfolio

Industry-leading software solutions for nuclear safety analysis

RELAP5/SCDAPSIM

Thermal Hydraulic Safety Analysis

RELAP5/SCDAPSIM Icon

The gold standard for thermal hydraulic safety analysis in nuclear power plants worldwide. Comprehensive software for severe accident analysis and thermal hydraulic simulation.

  • Comprehensive thermal hydraulic modeling
  • Severe accident progression analysis
  • Industry-standard for regulatory compliance

ASYST

Adaptive SYStem Thermal-hydraulics

Next-generation Best Estimate Plus Uncertainty (BEPU) accident analysis code for advanced reactor safety analysis and training. Developed through international ADTP consortium collaboration.

  • Integrated Uncertainty Analysis (IUA)
  • Interactive 3D visualization with RHYS
  • LWR to advanced reactor support

RHYS

Graphical Interface for ASYST & RELAP/SCDAPSIM

RHYS Icon

Cutting-edge graphical interface revolutionizing ISS system codes workflow. Optimizes performance for ASYST and RELAP5/SCDAPSIM from model construction to results analysis.

  • Node Viewer for system visualization
  • Real-time simulation control
  • Windows platform

FUELSIM

Fuel Behavior Simulation

FUELSIM Icon

Advanced fuel behavior simulation for detailed analysis of nuclear fuel performance under various operating conditions and accident scenarios.

  • Comprehensive fuel performance modeling
  • Thermal and mechanical behavior analysis
  • Integration with RELAP5/SCDAPSIM

Strip File Creator

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$29.99 - Perpetual License

Strip File Creator

RELAP/SCDAPSIM and ASYST Strip Files

Parse RELAP/SCDAPSIM and ASYST input decks to generate strip files. Eliminate manual processes and quickly define variables from input deck components.

  • Reads RELAP/SCDAPSIM and ASYST input decks (.i files)
  • 200+ built-in RELAP/SCDAPSIM variables
  • Generates strip files with CSV/FMTOUT formats
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Restart File Creator

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$29.99 - Perpetual License

Restart File Creator

Streamline Simulation Workflow

Resume ASYST and RELAP/SCDAPSIM simulations with confidence. Automatically detect checkpoints and generate clean restart files to save hours of computational time.

  • Automatic checkpoint detection
  • Safety-first commented restart points
  • Windows desktop app (Linux coming soon)
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Unlock the Power of Thermal Hydraulic Safety Analysis

Take your nuclear power plant and reactor safety to the next level with our industry-leading software solutions.

Join thousands of satisfied customers worldwide who trust RELAP for their thermal hydraulic safety analysis