Nuclear Laundry Using Supercritical Fluid Solutions

Cobalt and other metals, spiked onto lab coats, can be removed by supercritical fluid carbon dioxide (SC-CO 2 ) containing mixed chelating agents Cyanex 302 and dithiocarbamate, as well as by a water-in-CO 2 microemulsion. The extraction efficiencies for both methods can exceed 90%. The mixed-ligand approach suggests that effective metal extraction can be developed using two different ligands contributing to the solubility and stability of the resulting metal chelates in SC-CO 2 . The water-in-CO 2 microemulsion method does not require chelating agents. This approach significantly reduces the amount of liquid waste generation. Dynamic extraction time, flow rate, temperature of outlet restrictor, and collection solvent must be taken into consideration for the recovery efficiency. The potential of utilizing supercritical fluid solutions for cleaning 60 Co-contaminated protective coats used by nuclear power plant workers is discussed.