Development and Validation of Control Rod Drop Time Analysis Software CRAC

The control rod drop time during the process of reactor shutdown is very important for safety of the reactor. In order to be suitable for new structure design of fuel assembly in the HPR1000, a control rod drop time analysis software CRAC was developed by Nuclear Power Institute of China. The theoretical frame was constructed by using the onedimensional fluid dynamic equation and empirical mechanical resistance force model. The standard software development procedure was applied in the software design and coding stage. The experiment data of control rod drop time were used for the CRAC validation. The results show that the computational accuracy and safety margin of the CRAC meet the needs of the analysis of the control rod drop time criterion in HPR1000.