Simulation Of Chinese Experimental Fast Reactor Core Systems

Fast reactor means a lot to the nuclear industry in our country for it can improve the use factor of uranium resource and form a close nuclear fuel cycle system. The simulation of the Chinese Experimental Fast Reactor (CEFR) fills up domestic blank of simulation for fast reactor and it is also important for the nuclear industry. Under the background of simulation research for CEFR, this paper developed the core system simulation model based on the CEFR core systems. Then the model was debugged in the combination of other system models of CEFR.Firstly, a point reactor neutron kinetics model, including average temperature model,reactivity feedback model, sodium physical property model and PID control model, was set up. Besides, the implicit Euler method was proved to be a appropriate numerical algorithms to solve the point neutron kinetics equations. The logical models of reactor control system (RCS)and the reactor protect system (RPS) were established by logical block diagram. The model of nuclear measurement systems (NMS) in this paper were created aiming at the working principle and working process of the instruments. And then point neutron kinetics model was used to verify the model of RCS, RPS and NMS.Secondly, the model of RCS, RPS and NMS were modified to satisfy the three-dimensional diffusion model which was used in the model of the core system model eventually. Then, the interface programs between three-dimensional diffusion model and RCS,RPS, NMS model codes were developed using Fortran language to complete the core system model.Finally, the hardware and the core system model codes were combined and debugged to achieve hardware operation. Experiments were conducted during subcritical process, power conditioning process and accidents through core system model linked with primary coolant system model, secondary circuit model and other auxiliary system model. The results, on one hand, of the subcritical process and power conditional process demonstrate that the core system model simulate the process well. On the other hand, comparing with the safety analysis report of CEFR, the results of the accidents have a reasonable transient trend.Therefore the validity and the applicability of the core system was proved.