Uranium has been used for brightly colored ceramic glazes. Americium is used in smoke detectors, and I assume doping with small amounts of radioactive material

Uranium has been used for brightly colored ceramic glazes. Americium is used in smoke detectors, and I assume doping with small amounts of radioactive materials occurs in other applications where encouraging cold sparking or arcing is desired. Thorium is used in some (arc) welding rods: https://ehss.energy.gov/SESA/Files/corporatesafety/safety_bulletins/Bulletin_on_Thoriated_to_rccc200704.pdf https://ehss.energy.gov/SESA/Files/corporatesafety/safety_bu... https://www.epa.gov/radiation/radionuclide-basics-thorium https://www.epa.gov/radiation/radionuclide-basics-thorium Have a great day!