Preparation and melting of uranium from U3O8

In this paper, we report on the preparation and melting of uranium in association with a spent nuclear fuel conditioning process. U3O8 powder was electrochemically reduced in a mixture of molten LiCl–Li2O (∼3 wt.% of Li2O in LiCl) at 650 °C resulting in the formation of uranium and Li2O with a yield of >99%. When the powder of uranium with a residual LiCl–Li2O salt was heated in order to melt the metal, the uranium oxidation to UO2 due to the reaction with Li2O was observed. We were able to synthesize FeU6 by using a Fe based cathode during the U3O8 reduction procedure. FeU6 could be melted to below the temperatures where the oxidation of uranium by Li2O occurred. The idea of compound formation and melting is applicable to the melting and casting of a spent nuclear fuel which contains oxidative residual salts due to its conditioning in a molten salt.