From abstract: "The Darex process developed for the recovery of uranium from stainless steel-containing reactor fuels consists of three steps: (1) dissolution of the fuel material in dilute aqua regia, (2) removal of chloride from the solution to prevent corrosion of downstream stainless steel process equipment, and (3) adjustment of the nitrate solution to solvent extraction feed conditions."

The fabrication, irradiation and evaluation of the first two superheat fuel assemblies is described in detail. Experimental data indicate that, in general, the nuclear superheat fuel elements have performed satisfactorily under the testing conditions used. Certain problem areas which will influence future fuel element designs have been defined.