The Research and Design of Self-Diagnostic Function for NPP I&C System

Self-diagnosis is one of the most efficacious approaches to enhancing and ensuring the reliability of NPP I&C (Nuclear Power Plant Instrumentation & Control) systems. According to the requirements of IEC 61508 on self-diagnosis, a self-diagnosis design scheme for NPP I&C system is proposed in this paper. Firstly, the overall fault analysis of the NPP I&C system is carried out to identify the potential faults and derive the fault types to be diagnosed. Secondly, in the level of fault diagnosis design, the static and dynamic combination diagnosis design mechanism, the specific diagnosis design for different fault types is implemented, including the CPU core diagnosis design of LoongArch (loong architecture), and the diagnosis framework design suitable for multi-service scenarios are proposed. Finally, at the level of fault handling and warning, the design mechanism of the equipment's fault handling state transition, the system's data-oriented safety output, the fault bit information arrangement, and the local and network warning are proposed. This paper provides a systematic and detailed design scheme for the self-diagnosis of NPP I&C system, which can effectively improve the reliability of the system itself.