ABSTRACT

Waste and residue salts are generated in the production of uranium and plutonium metal and in plutonium metal purification. Magnesium fluoride salts that contain up to 5% of the feed uranium are produced during the production of depleted uranium metal. Currently these salts are disposed of directly as low-level waste (LLW). In the production of highly enriched uranium or plutonium metal, calcium fluoride salts are produced. These salts have relatively high melting points, and, therefore, are treated by aqueous means to separate the actinides from the waste salts. The plutonium pyrochemical processes, direct oxide reduction (DOR), molten-salt extraction (MSE), and electrorefining (ER), use lower-melting chloride-based salts. Waste and residue salts from these processes can be treated by either pyrochemical or aqueous technologies to separate the plutonium from the waste salt. This chapter covers the pyrochemical processing of plutonium residue salts.