title: Radioactive waste forms stabilized by ChemChar gasification: characterization and leaching behavior of cerium, thorium, protactinium, uranium, and neptunium.
abstract: The uses of a thermally reductive gasification process in conjunction with vitrification and cementation for the long-term disposal of low level radioactive materials have been investigated. gamma-ray spectroscopy was used for analysis of carrier-free protactinium-233 and neptunium-239 and a stoichiometric amount of cerium (observed cerium-141) subsequent to gasification and leaching, up to 48 days. High resolution ICP-MS was used to analyze the cerium, thorium, and uranium from 46 to 438 days of leaching. Leaching procedures followed the guidance of ASTM Procedure C 1220-92, Standard Test Method for Static Leaching of Monolithic Waste Forms for Disposal of Radioactive Waste. The combination of the thermally reductive pretreatment, vitrification and cementation produced a highly non-leachable form suitable for long-term disposal of cerium, thorium, protactinium, uranium, and neptunium.
authors.affiliation: Research Triangle Institute, Intl., 3040 Cornwallis Road, Research Triangle Park, NC 27709-2194, USA. tmarrero@rti.org
authors.forename: T W
authors.initials: TW
authors.lastname: Marrero
authors.forename: J S
authors.initials: JS
authors.lastname: Morris
authors.forename: S E
authors.initials: SE
authors.lastname: Manahan
mesh_terms: D002563:Cerium / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry*; D005720:Gamma Rays; D005898:Glass; D007700:Kinetics; D009405:Neptunium / Q000737:chemistry; D011478:Protactinium / Q000737:chemistry; D011850:Radioactive Waste / Q000032:analysis*; D012037:Refuse Disposal / Q000379:methods*; D013057:Spectrum Analysis; D013910:Thorium / Q000737:chemistry; D014501:Uranium / Q000737:chemistry
chemical_list: D011850:Radioactive Waste; D011478:Protactinium; D002606:Charcoal; D002563:Cerium; D014501:Uranium; D013910:Thorium; D009405:Neptunium