A method for the separation of uranium from uranium, zirconium and fission products, containing uranium fuel consumed elements

摘要

Uranium and zirconium are separated from spent nuclear fuel elements containing them by inserting the element within a fluidised bed of inert granular solids, introducing anhydrous hydrogen chloride to convert the zirconium to PICT:0925178/III/1 zirconium tetrachloride and recovering the latter, and thereafter introducing gaseous fluorine which reacts with the uranium and fission products to form a gaseous uranium hexafluoride-containing effluent gas which is fractionated to recover the uranium hexafluoride. The hydrochlorination of the zirconium may be carried out 350-450 DEG C. whilst the fluorination is suitably effected at 350-475 DEG C. As shown in Fig. 1 a jacketed reactor 10 is provided with a foraminous support 26 for supporting the zirconium clad uranium rod 22. The reactor is initially heated to 350-450 DEG C. by introducing liquid sodium into the jacket 16 whilst fluidising with a helium or argon stream; thereafter hydrogen chloride is introduced through line 28 whilst coolant is introduced through the jacket to control the exothermic reaction. Zirconium tetrachloride product is withdrawn via a filter 30 to line 32. Heated sodium is then passed through jacket 16 to raise the temperature to 400 DEG C. whereupon gaseous fluorine in a concentration of 5-100% of the gaseous phase is introduced through line 34; the uranium hexafluoride, plutonium hexafluoride and other volatile fission product fluorides are withdrawn through a line 36 to a distillation zone where uranium hexafluoride is recovered.