Risk Analysis of Single-Point Reactor Trip in the Steam Generator Feedwater System of an EPR Nuclear Power Plant and Redundancy Retrofit of Control Logic

The Steam Generator Main Feedwater System (ARE) is a critical system in the secondary circuit of a nuclear power plant, and the reliability of its control logic directly affects unit safety. During operation, the ARE systems of Units 1 and 2 at a certain EPR nuclear power plant were found to be at risk of reactor trip caused by a single instrument failure (e.g., the ARE narrow-range pressure transmitter), and some hardwired control signals lacked redundancy design. This paper systematically analyzes the aforementioned failure modes and proposes a comprehensive retrofit scheme based on control logic optimization and hardwired redundancy. The research findings can provide technical references for the control logic optimization of similar nuclear power units.