Method for plutonium-gallium separation by anodic dissolution of a solid plutonium-gallium alloy
AssigneeThe United States of America as represented by the United States Department of Energy
InventorsWilliam E. Miller, Zygmunt Tomczuk
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Abstract
Purified plutonium and gallium are efficiently recovered from a solid plutonium-gallium (Pu—Ga) alloy by using an electrorefining process. The solid Pu—Ga alloy is the cell anode, preferably placed in a moving basket within the electrolyte. As the surface of the Pu—Ga anode is depleted in plutonium by the electrotransport of the plutonium to a cathode, the temperature of the electrolyte is sufficient to liquify the surface, preferably at about 500° C., resulting in a liquid anode layer substantially comprised of gallium. The gallium drips from the liquified surface and is collected below the anode within the electrochemical cell. The transported plutonium is collected on the cathode surface and is recovered.
Claims18
A method for separating plutonium and gallium from a solid plutonium-gallium alloy utilizing an electrochemical cell, comprising the steps of:
- employing the solid plutonium-gallium alloy as an anode in the electrochemical cell,
- selecting a molten electrolyte or an electrolytic medium for the electrochemical cell where the electrolyte has a density less than that of gallium,
- maintaining a cell driving voltage below −0.9v in order to prevent the gallium from forming a salt within the electrolyte,
- electrotransporting plutonium from the anode through the electrolyte to a cathode;
- maintaining the cell at a temperature such that as plutonium ions migrate from a surface of the solid alloy a thin film of essentially liquid gallium forms on the surface of the solid alloy,
- allowing the liquid gallium to flow off of the surface of the alloy and collect under the solid anode.
A method for separating plutonium and gallium from a solid plutonium-gallium alloy utilizing an electrorefining process, comprising the steps of:
- providing an electrochemical cell having a molten electrolyte in contact with a cathode;
- inserting an anode comprised of the solid plutonium-gallium alloy having a surface within the molten electrolyte and in a spaced relationship to the cathode;
- establishing a voltage drop between the anode and the cathode;
- transporting the plutonium from the surface of the solid plutonium-gallium alloy, through the molten electrolyte, and to the cathode, whereby the surface is substantially depleted of plutonium;
- maintaining the molten electrolyte at a temperature sufficient to form a liquid layer on the plutonium depleted surface of the solid plutonium-gallium alloy, wherein the liquid layer is comprised of substantially of liquid gallium;
- collecting the liquid gallium, as the liquid gallium drips from the liquid layer;
- and
- recovering purified plutonium from the cathode.
Dependencies are inferred from the claim text.