Hydrogen permeation through walls with laminar-flow between two parallel flat plates

A tritium permeation window is an effective separator in the recovery of hydrogen isotopes in the fuel cycle of a D-T fusion reactor. Permeation through a plate type metal window has been numerically computed for laminar-flow. The results obtained were summarized by the relation between local or mean Sherwood number and reciprocal of Graetz number. The axial diffusion was taken into account in the calculations and the contribution of the permeation parameter of walls to the Sherwood number was discussed. Numerical calculations were performed for the selective permeation of tritium from tritium-helium mixtures in the D-T fuel cycle and from liquid lithium as the blanket fluid. It was pointed out that both the diffusion resistance through the metallic wall and the resistance of hydrogen diffusion in the fluid must be taken into consideration. (author)