THE APPLICATION OF DIFFUSIVITY DATA IN REDUCING THE HYDROGEN CONTENT OF GAMMA-EXTRUDED URANIUM BARS

摘要

The presence of hydrogen in uranium leads to difficulties in canning uranium cores at the nuclear reactor sites. One possible method of removing hydrogen from dingot uranium is to heat the metal under vacuum. The technical and economic feasibility of such a method de¬pends to a large extent on the temperature and time-at-temperature required to reduce the hydrogen content of the metal to an acceptably low level, which, in turn, depend on the diffusivity of hydrogen in the metal.nDiffusion coefficients for hydrogen in uranium that are given in the literature1'2 do not extend above 900°C, and only two determinations have been made in the qamma region. Davis1 re¬ported that the permeability of uranium membranes to hydrogen varied considerably with prior treatment and that exposure to hydrogen at operating temperatures from 500 to 700°C usually caused a slow increase in the diffusion rate.