Influence of 2D and 3D convection–diffusion flow on tritium permeation in helium cooled solid breeder blanket units

Numerical simulation of tritium permeation from breeding zones to the coolant in the helium cooled pebble-bed blanket is performed in this paper. 2D and 3D convection–diffusion models are developed to account for the effects of purge stream convection. Incompressible transient Brinkman model with variable permeability is used in flow calculation, and transient diffusion and convection equations are simulated for the tritium permeation analysis. Tritium partial pressure, concentration and permeation flux are evaluated. The influence of convection on permeation is evaluated under different flow conditions.