Multiscale granular-fluid dynamics in pebble bed reactor cores

Abstract

In addition to the study of three different practical designs, generic investigations on the scaling effect and pebble wear are also conducted. The coupled modeling approach developed in this thesis can provide better predictions of pebble flow packing density distribution, pebble flow velocity profile, and a more realistic pebble wear, by considering the effect from the coolant fluid on the pebble flow motion and contact force/stress. These pebble flow dynamic properties are the key parameters for the reliable analysis and design of pebble bed reactors.