Material contaminated with transuranic elements—artificially made, radioactive elements, such as neptunium, plutonium, americium, and others—that have atomic numbers higher than uranium in the periodic table of elements. Transuranic waste is primarily produced from recycling spent fuel or using plutonium to fabricate nuclear weapons. For related information, see the Backgrounder on Radioactive Waste.
Page Last Reviewed/Updated Monday, September 14, 2026