Nuclear Safety Logic Verification via Static and Dynamic Methods

The verification process is segmented into two distinct phases: static verification by property description and dynamic verification by simulation. Each phase serves a specific purpose - static verification establishes formal safety properties and invariants, while dynamic verification validates behavior under specific test cases. This segmentation allows the system to achieve SIL4 safety level by combining the rigorousness of static verification with the practical validation of dynamic verification.

Static verification by property description is performed as a preliminary action before dynamic verification. The formal verification language defines safety properties, invariants, and constraints that must be satisfied before the system undergoes simulation testing. This preliminary formal verification ensures that the basic safety architecture is correct before investing resources in extensive simulation testing.

The system divides verification efforts into two segments with different resource requirements. Static verification by property description is applied to critical safety functions and core logic components where formal verification is most beneficial. Dynamic verification by simulation handles less critical components and provides comprehensive behavioral testing. This segmented approach achieves SIL4 for safety-critical elements without requiring exhaustive static verification of all system components.

Different verification methods are applied to different parts of the system based on their safety criticality. High-safety static verification by property description is applied to the application logic, macro logics, and safety control functions. Lower-safety dynamic verification by simulation is applied to peripheral systems and non-critical components. This local quality approach optimizes verification resources while maintaining overall SIL4 safety level for the safety protection system.