Core Physics Calculation and Analysis for SNRE

Five different precise calculation models have been set up for Small Nuclear Rocket Engine（SNRE） core based on MCNP code,and then the effective multiplication constant,drum control worth and power distribution were calculated.The results from different models indicate that the model in which elements are homogeneous could be used in the reactivity calculation,but a detailed description of elements have to be used in the element internal power distribution calculation.The results of physics parameters show that the basic characteristics of SNRE are reasonable.The drum control worth is sufficient.The power distribution is symmetrical and reasonable.All of the parameters can satisfy the design requirement.