Permeation of Electrolytically Generated Hydrogen and Tritium Atoms through Lead

Abstract

Radiochemical and electrochemical evidence is presented that electrochemically generated tritium and hydrogen atoms permeate through lead foil at measureable rates at room temperature. The permeation process is controlled by diffusion through the metal lattice, Fick's First Law being obeyed by both H and 3H atoms. Using earlier measurements of the diffusivity of H in Pb, H and 3H concentrations of 4 × 10−7 and 9 × 10−13 g-atom cm−3 are computed for a current density of 53 mA cm−2 at the Pb cathode surface.The overall hydrogen-tritium separation factor, ST is apparently 0.3 ± 0.15, in contrast to Bockris and Srinivasan's 6.7 and 7.2 for cathodic gas evolution from acidic and alkaline media, respectively. Reasons are suggested for this large difference.