Reductive decontamination of magnesium fluoride

A method for separating radioactive components from magnesium-fluoride residues resulting from the magnesium reduction or uranium fluoride, comprising:

• (a) charging a container with radioactive magnesium-fluoride residues, at least one reactant selected from the group consisting of magnesium, magnesium alloys, lithium, calcium, barium, strontium, and the rare-earth metals, and with carbon, (b) heating the said container, in an inert atmosphere, until substantial melting of said residues is achieved thus causing said residues to react with said at least one reactant and carbon to form molten MgF.sub.2 and uranium carbide, and (c) separating the resulting uranium carbide, which is essentially insoluble in the molten MgF.sub.2, from said molten MgF.sub.2, which is thus substantially radioactive free.