Actinides in metallic waste from electrometallurgical treatment of spent nuclear fuel

Argonne National Laboratory has developed a pyroprocessing-based technique for conditioning spent sodium-bonded nuclear-reactor fuel in preparation for long-term disposal. The technique produces a metallic waste form whose nominal composition is stainless steel with 15 wt.% Zr (SS-15Zr), up to ∼ 11 wt.% actinide elements (primarily uranium), and a few percent metallic fission products. Actual and simulated waste forms show similar eutectic microstructures with approximately equal proportions of iron solid solution phases and Fe-Zr intermetallics. This article reports on an analysis of simulated waste forms containing uranium, neptunium, and plutonium. For more information, contact Dawn Janney, Argonne National Laboratory-West, P.O. Box 2528, Idaho Falls, ID 83403-2528; (208) 533-7478; fax: (208) 533-7863; e-mail dawn.janney@anlw.anl.gov.