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
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
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
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
Bundle & Save$29.99 - Perpetual License
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
Restart File Creator
Bundle & Save$29.99 - Perpetual License
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)
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
References & Resources
ISS software supports compliance with regulatory requirements from the U.S. Nuclear Regulatory Commission (NRC) and international standards set by the International Atomic Energy Agency (IAEA). Our codes build on foundational research from Idaho National Laboratory (INL) and are used in projects supported by the U.S. Department of Energy (DOE).