Numerical Simulation of Reactor Neutron Noise Based on Discrete Ordinate Finite Element Method

Abstract

At present, the technology of reactor neutron noise is developing rapidly, which can not only be used to measure some intrinsic parameters of the reactor core, but also be used for core fault diagnosis. The theoretical solution of reactor neutron noise is of great significance for providing information on the directivity of core faults, and its analytical solution is extremely difficult or even impossible. Therefore, it is necessary to study the numerical simulation method of reactor neutron noise. In this work, the governing equations of the neutron noise problem are firstly established based on the discrete ordinate finite element theory, the equations take the reactor steady-state parameters and the core disturbance cross-section as input parameters. Secondly, the frequency domain solver FrequencyDomain_SNSolver of neutron noise is developed, which is capable of acquiring steady-state parameters, reading disturbance cross-section and calculating neutron noise. Finally, for a calculation case of an experimental reactor core, the neutron noise distribution and spectrum under perturbation are obtained by using the developed FrequencyDomain_SNSolver. This work can provide some reference and technical support for related research.