Investigation on the Frequency-Dependent Response of Neutron Noise in 2-D MSR

This paper mainly studies the frequency-dependent response of neutron noise to perturbation in general case in a full-sized cavity type Molten Salt Reactor (MSR). The previous works mainly discussed the situation in one dimension, for its simplexes to be calculated and can give some qualitative analysis, but it’s not enough to analysis the real situation in the MSR. Hence a 2-D cylindrical coordination is utilized in this paper. We also considered the influence of different fluid velocity and different height-diameter ratio on the static and dynamic condition. For simplification, here we use diffusion equations with one-group 2-D neutron flux and precursor, and the perturbation is generated in the axial line along the flow direction, the fluid materials set as homogeneous. In a full-sized system, since the coupling is tighter, closed-form results can’t be found, we can only give out the theoretical expression or numerical results.