Conceptual design of dynamic emergency operating procedural system for NPPs: Integration of dynamic task management and safety monitoring

This study proposes a dynamic emergency operating procedural system to address the limitations of static, paper-based emergency operating procedures in nuclear power plants. Despite digital main control rooms, traditional procedures remain static and poorly suited to rapidly changing plant conditions. Operators must still search for relevant steps while ignoring those that do not apply, increasing workload and delaying decisions. The static format also hinders real-time tracking and verification, risking omission of safety-critical actions. To resolve these issues, this study developed the Emergency Guidance Intelligent System (EGIS), which provides real-time monitoring and required task blocks. EGIS comprises three core functions: the Task Block Browser, which delivers only necessary tasks in real-time using a functional-hierarchical task grouping framework; the Critical Safety Function Score Evaluator, which evaluates critical safety functions using fuzzy logic; and the Plant Status Monitor, which visualizes system status and consequence through Multilevel Flow Modeling. EGIS was verified using the Compact Nuclear Simulator with a Loss of Coolant Accident scenario. The results demonstrated that EGIS reduced operation time compared to conventional procedures while effectively replacing the role of traditional paper-based procedures. EGIS is expected to enhance the safety and efficiency of emergency operating procedures in nuclear power plants.