The Influence Mechanism of Space-Time Kinetics of ADS Subcritical Reactor under Beam Transients

Abstract

The space-time kinetics of ADS Subcritical Reactor (ADSR) under beam transients play an important role in ensuring the reliability of the control and safety system of the accelerator-driven subcritical system (ADS). In order to elucidate the effect of high heterogeneity of neutron flux density in space-time on the neutron space-time kinetics of ADSR under different subcriticality and beam transients, in this paper, the multimode core few-group constants, which is more adaptable to the beam transients, is used to investigate the mechanism of neutron flux density, core few-group constants, and kinetic parameters of ADSR under the synergistic effect of external neutron source, subcriticality, and the beam transients. The results show that with the deepening of the subcriticality, with the increasing role of external neutron source, the neutron flux density of the ADSR has a higher heterogeneity of space-time, which leads to a larger difference in the core few-group constant library of different modes, and thus a larger difference in the kinetic parameters (especially the neutron generation time) of different modes. Therefore, in the study of the influence mechanism of neutron space-time kinetics of ADSR under beam transients, the multimode core few-group constants should be used, and the influence of external neutron source and subcriticality on the kinetic parameters, especially the neutron generation time, should be emphasized.