Research On Method Of Neutron Dynamics Of Accelerator Driven Sub-Critical System

Accelerator driven sub-critical system takes spallation neutrons to drive blanket system, is one of the effective way of transmutation of nuclear waste.The existence of the high energy spallation neutron source can make the distribution of core power non-uniform and neutronics processcomplexity. The results of traditionalmethod depends on the high energyspallationneutron spectrum and the accuracy of the sub-critical reactor core neutron macroscopic cross section.In order to increasethe method of the study ofthe dynamic characteristics of ADS, theneutron time-space dynamics method combined with the MCNPprogramwill be used.The method is to calculate theneutron flux distribution of ADS within the MCNP, and some parameters through some empirical formulas calculating, which used to calculateamplitude function. the amplitude function of ADS is calculated by numerical method. This method is used to simulate the neutron kinetics of ADS of source step change.And the results of this method and the results of are the same.A program is written to simulate the transient behavior of ADS based on point equation.In order to verify the correct of the program, the LBE-ADS reactor beam interrupt operating conditions is Simulated.The large loss of coolant may have a significant impact on the safety of a subcritical reactor, can be taken off the accelerator method to ensure safety. Changes of accelerator beam increases and the coolant inlet temperature will lead to changes in sub critical reactor power, but will soon reach a new steady state.