Section 06 Products of the chemical or allied industries 28 Inorganic chemicals; organic or inorganic compounds of precious metals, of rare-earth metals, of radioactive elements or isotopes 28 44 Radioactive chemical elements and radioactive isotopes (including the fissile or fertile chemical elements and isotopes) and their compounds; mixtures and residues containing these products. 28 44 50 Spent (irradiated) fuel elements (cartridges) of nuclear reactors Commodity Code Description 28 44 50 00 Spent (irradiated) fuel elements (cartridges) of nuclear reactors