Integrated simulation of tritium permeation in solid breeder blankets

Numerical simulation of co-permeation of tritium and hydrogen from breeding zones to the coolant in the helium cooled pebble-bed blanket is performed in this paper. 3D multi-species convection–diffusion models integrated with thermal-fluid analysis in porous media are assessed and then used to estimate the associated tritium permeation for a solid breeder blanket module. Benchmark calculations give a reasonable agreement on the co-permeation rates with the experimental data. Simulation in a TBM unit show that purge gas flow can strongly affect tritium transport, increasing the purge flow velocity is an effective method to reduce tritium permeation to the coolant. In the case where hydrogen is added to the purge gas stream to promote tritium release, the co-permeation of H2, T2, and HT are taken into account in the permeation simulation, results show that permeation flux of T–T molecules is reduced due to the effect of co-permeation of hydrogen.