title: Decontamination of uranium-contaminated waste oil using supercritical fluid and nitric acid.
abstract: The waste oil used in nuclear fuel processing is contaminated with uranium because of its contact with materials or environments containing uranium. Under current law, waste oil that has been contaminated with uranium is very difficult to dispose of at a radioactive waste disposal site. To dispose of the uranium-contaminated waste oil, the uranium was separated from the contaminated waste oil. Supercritical R-22 is an excellent solvent for extracting clean oil from uranium-contaminated waste oil. The critical temperature of R-22 is 96.15 °C and the critical pressure is 49.9 bar. In this study, a process to remove uranium from the uranium-contaminated waste oil using supercritical R-22 was developed. The waste oil has a small amount of additives containing N, S or P, such as amines, dithiocarbamates and dialkyldithiophosphates. It seems that these organic additives form uranium-combined compounds. For this reason, dissolution of uranium from the uranium-combined compounds using nitric acid was needed. The efficiency of the removal of uranium from the uranium-contaminated waste oil using supercritical R-22 extraction and nitric acid treatment was determined.
authors.affiliation: Green Nuclear Research Laboratory, Kyung-Hee University, Sehcheon-dong, Gigeung-gu, Yongin-si, Gyeonggi-do 446-701, Korea.
authors.forename: Jinhyun
authors.initials: J
authors.lastname: Sung
authors.forename: Jungsoo
authors.initials: J
authors.lastname: Kim
authors.forename: Youngbae
authors.initials: Y
authors.lastname: Lee
authors.forename: Jeunggun
authors.initials: J
authors.lastname: Seol
authors.forename: Jaebong
authors.initials: J
authors.lastname: Ryu
authors.forename: Kwangheon
authors.initials: K
authors.lastname: Park
mesh_terms: D003666:Decontamination; D017942:Nitric Acid / Q000737:chemistry*; D009821:Oils / Q000302:isolation & purification*; D011850:Radioactive Waste; D012997:Solvents / Q000737:chemistry*; D014501:Uranium / Q000737:chemistry* / Q000302:isolation & purification*; D017974:Uranium Compounds / Q000737:chemistry
chemical_list: D009821:Oils; D011850:Radioactive Waste; D012997:Solvents; D017974:Uranium Compounds; D017942:Nitric Acid; D014501:Uranium