Reliability Analysis for the Filling and Discharging System in the Primary Circuit of the Lead-bismuth Fast Reactor

The filling and discharging system in the lead-bismuth fast reactor which is filled with liquid metal containing radioactive materials, is designed to adjust the coolant level in the reactor vessel, so it is an important system for ensuring the safety of reactor operation and requires high level of safety and reliability. This study performed preliminary reliability analysis of the filling and discharging system in the lead-bismuth fast reactor whose conceptual design was completed by Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences by using Fault Tree Analysis method. Minimal Cut Sets and failure probability of the filling and discharging system were obtained by using Reliability and Probabilistic Safety Assessment program RiskA, which was developed by FDS Team. Some other quantitative analysis results were also obtained, including importance, sensitivity analysis, and uncertainty analysis for the result. The key part which affect the reliability of the system in the concept design was found and the calculation result can provide reference for optimization of the filling and discharging system.