Optimization of Shuffling Strategy for Rod Cluster Control Assemblies

Shuffling strategy is not considered for the control rod assembly in the operating nuclear power plants in China at present. The position of Rod Cluster Control Assemblies (RCCAs) is fixed with fuel assembly in the core, resulting in inhomogeneous irradiation, which will affect the safe operation and economic benefits of NPPs. The paper describes the shuffling strategies with the application of CRABE V3.3 which is used in lifetime analysis of CPR1000. By comparing, if a shuffling strategy is used, the design lifetime of the power control RCCAs significantly increased to 200% and temperature control RCCAs are also improved. RCCAs can be optimized by shuffling strategy considering the situation during refueling outage. RCCAs lifetime can be optimized and the safety of NPPs can be improved in this way.