Packing density of the tritium breeder pebble beds are closely related to the effective density of the lithium atom in the breeding cavities. And the higher the density of lithium atoms the higher the tritium breeding ratio. Therefore, in this work, the effect of vibration parameters on the densification behavior of tritium breeder pebble beds were investigated by Discrete element method (DEM) simulation. The findings indicate that vertical vibration can substantially enhance the densification of the mono-sized pebble bed. The average packing factor of the vibrated bed attains it’s maximum when the periodic boundary is employed. As the vibration frequency and amplitude increase, the average packing factor of the pebble bed experiences an initial rise, followed by a subsequent decrease. The effect of vibration intensity displays a similar pattern. Furthermore, as the vibration time is extended, the average packing factor of the pebble bed undergoes a gradual increase, ultimately reaching 0.6409 when the vibration time extends 200 s. The state is distinguished by the random close packing of mono-sized pebble beds. The findings presented in this paper contribute to the optimization of the fabrication and assembly process of solid blanket for fusion reactors.
Local packing factor distribution of the vibrated pebble beds with frequencies of: a) 0 Hz, b) 10 Hz, c)20 Hz, d) 100 Hz.
Baoping Gong, Hao Cheng, Juemin Yan, Long Wang, Qixiang Cao, Long Zhang, Jiming Chen, Yongjin Feng. Densification behavior of tritium breeder pebble beds under vibration: effect of vibration parameters, Nuclear Materials and Energy, 2025, 101997. [ PDF, DOI, Link]