Fast spectrum small nuclear reactor core transient multi-physics coupling method and computer program product

The invention relates to a fast spectrum small nuclear reactor core transient multi-physics coupling method and a computer program product, and aims to solve the technical problems that the existing nuclear reactor transient analysis is single in consideration factor, low in result credibility and incapable of realizing accurate and comprehensive evaluation. The method comprises the following steps: 1, constructing a neutron microscopic cross section database of a nuclear reactor core; constructing a neutron transport kinematics, thermal hydraulic and mechanical computational grid model; setting physical property parameters of thermal hydraulic calculation and mechanical calculation; 2, setting preset total simulation time, and determining initial conditions and boundary conditions of calculation; 3, time stepping is carried out, and the current time is updated; calculating the power density distribution, the temperature distribution and the density distribution of the reactor core at the current time and the