NSSS System Modeling

THBuilder™

From normal operation to accident scenarios, THBuilder delivers comprehensive simulation of the reactor primary system (NSSS) through high-precision thermal-hydraulic modeling.

THBuilder is an advanced simulation modeling tool that faithfully represents, based on physical principles, the operational characteristics, design conditions, and accident responses of key thermal-hydraulic systems within nuclear power plants.
Designed within a GUI-based visual environment, the platform enables easy execution of the entire workflow—from model configuration and testing to multi-condition analysis.

The platform supports modeling and simulation across the full spectrum of operating conditions—including normal, transient, abnormal, and emergency states—and is widely utilized for education and training systems, design verification, and accident response simulators.

Key Messages

Standardized Model Configuration Based on a Visual Environment

Provides a visual, GUI-based block diagram (component) environment such as Orchid® ME.
Enables intuitive configuration, review, and modification of complex NSSS systems. Supports template-based configurations tailored to various thermal-hydraulic analysis objectives.
→ Allows any user to rapidly standardize models and perform repeated analyses efficiently.

High-Fidelity Simulation Accuracy and Stability

Applies high-precision computational logic based on mass and energy conservation principles.
Provides quantitative analysis across a wide range of thermal-hydraulic events, including normal, abnormal, and dual-failure conditions.
Ensures high-speed computation and numerical stability for transient scenarios.
→ Maintains reliable model analysis even under severe thermal transient conditions.

Support for Multiple Reactor Types and Operational Scenarios

Supports systems and characteristics of various reactor types, including PWR, BWR, and CANDU.
Enables modeling of diverse scenarios such as loss of coolant, rapid cooldown, and shutdown cooling.
Covers all operating conditions from startup to full power operation.
→ Replicates real plant operational scenarios in a manner closely aligned with real-time behavior.

Key Application Areas

Development of NSSS system simulators for nuclear power plants
Configuration and operation of primary system scenarios for education and training
Experimental analysis modeling and validation for research applications
Design optimization support tools based on safety analysis

Key Expected Benefits

Enhanced system analysis expertise through simulations closely aligned with actual plant operating conditions
Improved accident response capability by validating response scenarios through integrated analysis of diverse emergency operating conditions
Integrated implementation of education and training systems
Architectural design enabling integration with nuclear power plant simulators and training equipment
Scenario-based design review, allowing application of thermal-hydraulic analysis models during new reactor design phases