Simulation of a CANDU reactor approach to criticality after a long shutdown

This study addresses the approach to criticality of CANDU reactors during their startup after a long shutdown. The simulation study is based on the point kinetics model, which represents the prompt neutron kinetics and 17 delayed neutron precursor groups. The parameters of the neutronic model used in this model, are chosen to be the same parameters of Bruce-A reactor fresh core to simulate its start-up. Other dynamics were also included in the model such as the Gadolinium extraction dynamics, and the Xenon dynamics. The factors, which affect the core approach to criticality, have been well simulated and analyzed separately. (author)