Fluoride Action Network

Uranium Enrichment–Gaseous Diffusion Process

Source: Uranium World Blogspot | July 14th, 2009
Industry type: Nuclear Industry

The gaseous diffusion is one among the uranium enrichment process, where the gaseous diffusion enrichment plant, the solid uranium hexafluoride (UF6) from the conversion process is heated in its container until it becomes a liquid. The container becomes pressurized as the solid start melts and the uranium hexafluoride gas fills the top of the container. Where this uraniumF6 gas is slowly fed into the plant’s pipelines where it is pumped through special filters called barriers or porous membranes. The holes in the barriers are very small such that there is barely enough room for the uranium hexafluoride gas molecules to pass through.

The isotope enrichment occurs when the lighter uranium hexafluoride gas molecules (with the U-234 and U-235 atoms) likely to diffuse faster through the barriers than the heavier uranium hexafluoride gas molecules containing uranium-238. One barrier is not enough, though it takes several hundreds of barriers, one after the other, before the uranium hexafluoride gas contains enough uranium-235 to be used in reactors.

At the end of the process, the enriched uranium hexafluoride gas is taken back from the pipelines and condensed back into a liquid that is poured into containers. The uranium hexafluoride is then permitted to cool and solidify before it is transported to fuel fabrication facilities where it is turned into fuel assemblies for nuclear power reactors.

The major hazards in gaseous diffusion plants include the chemical and radiological hazards of uranium hexafluoride release and the potential for mishandling the enriched uranium, which may create a critical accident i.e. inadvertent nuclear chain reaction.