Comment Re:Perhaps it wouldn’t pass today’s .. (Score 3, Informative) 286
Raw uranium ores are a lot more radioactive than pure uranium oxides like yellowcake (U3O8) because of all the shorter-lived isotopes that have built up in the ore bodies from a billion years or so of decays of U-235 (700 million years) and U-238 (over 4 billion years). The other thing is that solid lumps of uranium are a good shield against radiation and the alpha particles resulting from decay events a millimetre or two under the surface are unlikely to escape the lump of metal and be dangerous.