Numerical simulation of stress properties on high-yield fast-neutron-burst reactor in super-prompt-critical condition

The performance of fast burst reactor (FBR) is mainly restricted by the physical damage caused by the mechanical shock. The smaller burst width and larger fission yield in high-yield FBRs indicate more significant stress variation. To obtain the temporal and spatial distributions of stress/strain of burst in the high-yield FBR and to provide technical support for the design and safety analysis of new-type FBRs, the neutronic calculation based on the point kinetic approximation and Monte Carlo method is first performed to obtain the temporal and spatial distributions of fission power in the cylindrical FBR Godiva IV, the three-dimensional thermoelastic behavior in the burst is then simulated by using the finite element method software ANSYS Mechanical. The dynamic response of stress in material component is obtained and analyzed. The results show that the cylindrical fuel will suffer a stress wave during the burst and the maximum stress occurs in the radial cracking of central fuel rings. (authors)