Industry Standard Since 1995

RELAP5/SCDAPSIM

The Gold Standard for Thermal Hydraulic Safety Analysis

RELAP5/SCDAPSIM Icon

Comprehensive Nuclear Safety Analysis

RELAP5/SCDAPSIM is the industry-leading thermal hydraulic safety analysis code trusted by nuclear facilities worldwide for regulatory compliance and severe accident analysis. Combining RELAP5's robust thermal hydraulic modeling with SCDAP's severe accident progression capabilities, this integrated code provides unparalleled accuracy for nuclear safety engineering.

RELAP5/SCDAPSIM

Regulatory Compliance

Industry-standard software accepted by regulatory bodies worldwide for safety analysis and licensing.

Severe Accident Analysis

Advanced SCDAP capabilities for core degradation, melt progression, and fission product release.

Global Standard

Trusted by nuclear facilities in over 30 countries for safety evaluation and accident analysis.

Comprehensive Modeling Capabilities

Advanced physics models for complete nuclear safety analysis

Thermal Hydraulic Modeling

Best-estimate thermal hydraulic analysis for light water reactors under operational transients and postulated accidents. Includes full two-phase flow modeling with advanced constitutive correlations.

  • Two-phase flow with six-equation model
  • Flow regime mapping and transitions
  • Critical flow and choking models

Severe Accident Progression

Comprehensive SCDAP modeling for severe accident scenarios including core degradation, melt relocation, and debris bed formation with coupled thermal hydraulics.

  • Fuel rod oxidation and hydrogen generation
  • Core melt progression and relocation
  • Lower plenum debris bed behavior

Extensive Component Library

Comprehensive library of validated component models for all major reactor systems including pumps, valves, heat structures, and control systems.

  • Pumps, valves, and flow control devices
  • Heat structures and heat exchangers
  • Control systems and trip logic

Fission Product Behavior

Track fission product release, transport, and deposition throughout the reactor coolant system for source term analysis and radiological consequence assessment.

  • Fuel-to-coolant fission product release
  • Aerosol transport and deposition
  • Chemical species tracking

Advanced Visualization & Post-Processing

Powerful visualization tools for comprehensive results analysis

Advanced Plot View 1
Advanced Plot View 2
Advanced Plot View 3
Advanced Plot View 4

Comprehensive Post-Processing Tools

Time Series Plotting

Plot any variable from simulation results with multiple traces, custom scales, and export capabilities.

Data Export

Export simulation results to CSV, Excel, or ASCII format for further analysis and reporting.

Animation Tools

Create animations of transient behavior for presentations and detailed analysis review.

Applications Across Nuclear Safety Analysis

Licensing Analysis

Design basis accidents and safety evaluation reports for regulatory submissions.

Beyond Design Basis

Severe accident scenarios including station blackout and LOCA with core damage.

Validation Studies

Code validation against experimental data and plant measurements.

Training & Education

Academic instruction and operator training program development.

Plant Modifications

Safety impact assessment for plant design changes and power uprates.

PRA & Risk Analysis

Probabilistic risk assessment and risk-informed decision making.

Technical Specifications

Proven technology with continuous development and validation

Platform Support

Windows, Linux, Unix

Programming Language

FORTRAN (highly optimized for performance)

Reactor Types

PWR, BWR, VVER, CANDU, advanced reactor designs

Development History

40+ years of continuous development and validation

Key Features

  • Best-estimate thermal hydraulics with validated correlations
  • Integrated severe accident modeling with SCDAP
  • Extensive validation against experimental data
  • Regulatory acceptance worldwide
  • Active user community and support network
  • Comprehensive documentation and training materials

Trusted Worldwide

Used in over 30 countries for nuclear safety analysis

Experience the Industry Standard

Join leading nuclear facilities worldwide in using RELAP5/SCDAPSIM for thermal hydraulic safety analysis.

Need training or support? Contact our expert team