Evaluation of error detection coverage and fault-tolerance of digital plant protection system in nuclear power plants

Recently, traditional analog-based safety-related instrumentation and control (I&C) systems in nuclear power plants (NPPs) have been replaced with modern digital-based systems. Due to the digitalization of nuclear I&C systems, the safety assessment has become a major issue, as it is crucial to the system's reliability. In the safety assessment of the digitalized system, evaluation of error detection coverage and fault-tolerance are critical factors. For the evaluation, we use C++ based hardware description instead of a board with integrated circuit components. We select the digital plant protection system (DPPS) in NPPs as a target system. Permanent fault is used as a possible fault in the system and some error detection methods are used to detect errors. From the experiment, we confirmed that the proposed approach can evaluate the error detection coverage and the fault-tolerance of DPPS in NPPs.