Research on Operation Optimization of AP1000 Boric Acid Makeup Subsystem

Compared with the traditional second-generation unit, the boric acid makeup subsystem of AP1000 unit has advanced design concept and simple system structure. However, in the actual operation and maintenance process of the unit, boron deviation alarms frequently occur, which affects the safe operation of the unit. It is necessary to further optimize the system's operational performance. This study aims to identify the key factors that influence the performance of the subsystem by constructing a comprehensive database of unit operations. Subsequently, simulation models are established using Flowmaster and RinSim software, and the impact mechanisms of various factors are analyzed through simulation experiments. The results show that the relative pressure of demineralized water and boric acid at the inlet of the three-way valve is the key factor to determine the effectiveness of the boron concentration control. Additionally, the performance of pressure relief valve, boron tank liquid level, and measurement instrument deviation are also important influencing factors, while the effects of regulating valve and makeup water pump are relatively small. Based on the analysis results, this study further explores operational optimization strategies for the system and provides optimization schemes from both short-term and long-term perspectives. The analysis results and optimization schemes of this study can provide reference for optimizing unit operation regulations or technical transformation.