Processing [g21f-9/06] Patents (Class 976/DIG380)
  • Patent number: 6040491
    Abstract: In a method and an apparatus for dewatering and containing radioactive, aqueous waste (44), the latter is introduced into a filtration container (12) and is ultimately disposed of in a disposable container structure (12, 48, 50), which comprises the filtration container (12) holding the dewatered waste (44), as well as an outer container (50) enclosing the filtration container (12). The filtration container is an inner sack (12) having a bottom (13) which is provided with a straining cloth and through which essentially all the dewatering is carried out. After the dewatering operation has been completed, the inner sack (12) is sealed and placed in the outer container (50) in order to be ultimately disposed of. For purposes of cleaning, the filtration water (17) may be recirculated through the waste during the dewatering operation.
    Type: Grant
    Filed: September 30, 1997
    Date of Patent: March 21, 2000
    Assignee: Vattenfall AB
    Inventor: Sony Sjowall
  • Patent number: 5564105
    Abstract: A borated aqueous solution from a nuclear reactor coolant system dilute chemical-decontamination process or from an equipment washing process which has been contaminated with radioactive metals or heavy metals including cobalt, nickel, chromium, iron, manganese, lead or mercury and with a chelating agent, detergent or soap is treated with an oxidizing agent to oxidize the chelating agent, detergent or soap and to precipitate the contaminant metals. The contaminant metals are then separated from the solution by centrifugal filtration, micromembrane belt filtration or magnetic separation. Advantageously, a very small volume of precipitate may then be buried and the decontaminated solution may be recycled or further treated and released for other uses.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: October 8, 1996
    Assignee: Westinghouse Electric Corporation
    Inventors: William M. Alvino, David C. Grant, Edward J. Lahoda, William A. Byers, Robert D. Burack
  • Patent number: 5564103
    Abstract: A process for removing liquid from depleted ion exchange bead resin includes the steps of: transferring a slurry containing at least 10 volume % of contaminated ion exchange resin beads from storage (10) having a particle size range from 300 micrometers to 1000 micrometers to a blending tank (14) to provide a homogeneous slurry which is fed to a grinder (16) usually by means of pumps (13 and 17), where the beads are fractured, and reduced in size, where no more than 33% of the fractured beads have a relatively similar diameter, allowing subsequent random packing compression; and then passing the processed slurry to a dewatering system (18) where it is separated into liquid (20) and highly compressible waste (22).
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: October 8, 1996
    Assignee: Westinghouse Electric Corporation
    Inventor: Donald F. Gagel
  • Patent number: 5523514
    Abstract: The invention relates to the dissolving of plutonium and/or other radioactive elements in an aqueous solution by microwave heating.According to the invention, solid or liquid products containing plutonium and/or other radioactive elements are introduced into a container (7) containing an acid solution, comprising hydrofluoric acid and nitric solution, followed by the microwave heating of the solution containing these products using a chamber or tank (5) placed in a tight enclosure (1), which is supplied with microwaves by means of a coaxial cable or a waveguide (11) connected to the generator (9) located outside the enclosure.The solid products can be plutonium dioxide PuO.sub.2 or organic or mineral radioactive waste materials such as gloves, cellulose products, ion exchange resins, etc. The liquid products can be contaminated organic solvents such as tributyl phosphate in dodecane.
    Type: Grant
    Filed: April 13, 1993
    Date of Patent: June 4, 1996
    Assignee: Compagnie Generale des Matieres Nucleaires - Cogema
    Inventors: Gerard Cauquil, Michel Sourrouille
  • Patent number: 5411149
    Abstract: A process for aqueous biphasic extraction of metallic oxides and the like from substances containing silica. Control of media pH enables efficient and effective partition of mixture components. The inventive method may be employed to remove excess silica from kaolin clay.
    Type: Grant
    Filed: August 11, 1992
    Date of Patent: May 2, 1995
    Assignee: ARCH Development Corporation
    Inventors: David J. Chaiko, R. Mensah-Biney