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
Why Choose ISS?
From simulation to analysis, our integrated solutions support every phase of nuclear safety engineering
01
Industry-Proven Reliability
Trusted by nuclear facilities worldwide for regulatory compliance and safety analysis since 1995.
02
Severe Accident Modeling
Advanced SCDAP capabilities for core degradation, melt progression, and fission product release analysis.
03
Modern Interfaces
Intuitive GUI tools like RHYS streamline workflows from model construction to results visualization.
04
Expert Support & Training
Comprehensive workshops, documentation, and dedicated technical support from experienced engineers.
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
Integrated System Analysis Tool
Comprehensive modeling and simulation capabilities for complex systems. Powerful platform for multi-physics analysis with intuitive interfaces.
- Multi-physics system modeling
- Graphical model development interface
- Advanced visualization and post-processing
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
$199.00 - 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
$199.00 - 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