Processing [g21f-9/30] Patents (Class 976/DIG392)
  • Patent number: 5826203
    Abstract: A method for solidifying a radioactive iodine-containing waste, in which volatilization of radioactive iodine outward can be suppressed during solidification, and a solidified waste having a high level of confinement of radioactive iodine and a long term stability can be obtained. The method comprised mixing a granular waste containing radioactive iodine, e.g. a granular iodine adsorbent having radioactive iodine adsorbed and collected thereon, with a metal powder, e.g. a copper powder, having a corrosion resistance in an environment of solidified waste disposal, filling the resulting mixture in a metal capsule, and subjecting the whole to hot isostatic pressing to effect solidification. In the resulting solidified waste, particles of the radioactive iodine-containing adsorbents are dispersed and retained in the sintered matrix of the metal powder formed through the isostatic pressing.
    Type: Grant
    Filed: July 14, 1997
    Date of Patent: October 20, 1998
    Assignee: Doryokuro Kakunenryo Kaihatsu Jigyodan
    Inventors: Masahiro Fukumoto, Manabu Kanzaki
  • Patent number: 5750081
    Abstract: A method of extracting metal species from a metal species containing medium which comprises contacting the medium with an extractant solvent which comprises a supercritical fluid and a complexant for solubilizing metal species in the said medium and also a conditioning agent for changing the oxidation state of the metal species.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: May 12, 1998
    Assignee: British Nuclear Fuels plc
    Inventor: Neil Graham Smart
  • 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: 5414196
    Abstract: A cementitious surface contaminated with a radioactive substance is decontaminated by applying a micro-organism to the surface to degrade the surface. The residue which contains the radioactive substance is then removed by suction, scraping, brushing or abrasion blasting. The micro-organism might comprise an aerobic sulphur oxidising bacteria, or an anaerobic sulphate reducing bacteria, or a mixture thereof. Action of the micro-organism can be stopped as necessary by heating, or by depriving the micro-organism of nutrients.
    Type: Grant
    Filed: October 16, 1992
    Date of Patent: May 9, 1995
    Assignee: British Nuclear Fuels plc
    Inventor: Howard T. Jennings
  • 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