Uptake and Distribution of Tritium in Copper

Abstract

The uptake of tritium on the surface and in the bulk of copper upon exposure to a 50 % T/H mixture at 300 or 473 K was investigated using a chemical etching technique. Concentrations of tritium approaching saturation are achieved fairly rapidly in Cu even at low temperatures because of comparatively high diffusivity and low solubility of hydrogen in this material. The results were interpreted by a diffusion model. Most notorious are the very high concentrations of tritium on the topmost surface and subsurface. They were quantified by etching and confirmed by BIXS. In addition, there is evidence for tritium trapping in the subsurface region.Tritium-loaded copper specimens release tritium chronically at ambient temperature. The egress of tritium manifests in the gas phase almost exclusively as tritiated water.