The reactivity with uranium of coating layers by the thermal spraying method

The uranium ingot casting process is one of the steps which consolidate uranium deposits produced by electrorefiner in an ingot form in a pryprocessing technique. Since molten uranium metal reacts with a graphite crucible when the uranium is being dissolved, a graphite crucible cannot be used. Accordingly, a ceramic material must be selected which does not react with the dissolving uranium and this must be used as a coating material on the graphite crucible surface. As to this research, a reactivity experiments were performed between the coating layer and uranium by applying a thermal spray coating to the graphite material with alumina and YSZ ceramic material. As shown in the experimental result, the YSZ coating layer showed a stronger adhesive property on the side where there is no Ni–Al binding material. Moreover, no reaction was apparent between the YSZ coating layer and the uranium. Accordingly, the YSZ material and the process of thermal spray coating are considered to solve the reactive problem between uranium and a graphite crucible.