Abstract: A process for removing undesirable material such as a radioactive contaminant from an underlying material. A solution containing fluoroboric acid and a material which affects the fluoroboric acid solution oxidation potential (Eh) is contacted with the contaminant material to cause its removal. The contaminant material is removed from the fluoroboric acid solution by contacting the fluoroboric acid solution which has been contacted with the contaminant material with a cation exchange resin.

Abstract: A process for the decontamination of radioactive materials which process comprises the steps of: i) contacting the material to be decontaminated with a dilute carbonate containing solution in the presence of ion exchange particles which either contains or have a chelating function bond to them; and ii) separating the ion exchange particles from the dilute carbonate containing solution. The radioactive materials which are treated may be natural materials, such as soil, or man-made materials such as concrete or steel, which have been subjected to contamination.

Abstract: A method for the decontamination of a cementitious or a metallic surface having contaminants is described. The method comprises the steps of supplying to said surface at least one microorganism under conditions conducive to growth of said at least one microorganism; maintaining said conditions conducive to growth of said microorganism and the generation of an acid or other metabolite to degrade said surface to a desired depth; terminating said conditions conducive to growth upon achieving at least said desired depth of degradation; removing the products of said degradation; treating said degradation products; and, disposing of said treated degradation products wherein the at least one microorganism is a citric acid generating microorganism.

Abstract: Although a chelating agent solution having radioactive contaminants is solidified by mixing with cement and then stored, a vast storage place is required for storing an enormous amount of chelating agent solution. When such a chelating agent solution is treated with an ion-exchange resin, a large amount of ion-exchange resin is required, and a large amount of ion-exchange resin having radioactive contaminants is produced. The present invention thus provides a method of treating a chelating agent solution having radioactive contaminants, which can significantly decrease the amount of the chelating agent solution having radioactive contaminants, and which, when an ion-exchange resin is used, can significantly decrease the load on the ion-exchange resin without producing a large amount of ion-exchange resin having radioactive contaminants.

Abstract: A process for the recovery of chemical values, particularly uranium, nickel and/or radionuclides from process equipment theretofore employed in a uranium hexafluoride isotope enrichment cascade. Preferably, the process is carried out, in situ, at subatmospheric pressure employing the existing process equipment from which the chemical values are to be recovered. In one aspect, the process includes recovery of uranium values employing a gaseous fluorinating agent at subatmospheric pressure, followed by recovery of nickel values employing a gaseous reactant comprising a mixture of carbon monoxide and a promoter, preferably hydrogen sulfide and at subatmospheric pressure.

Abstract: An apparatus for cleaning a separator is disclosed. Generally, the apparatus includes a vessel connected to a well that produces an effluent. The vessel is used for separating the effluent. Also included is a discharge member which is attached within the vessel for discharging a liquid onto solids located at the bottom of the vessel, and a drain adapted for draining the solids from the bottom of the vessel. The apparatus may further include a chemical injection device, operatively associated with the discharge member, for injecting a radioactive dissolution chemical. A process for cleaning the vessel and treating the entrained solids of the effluent with the radioactive dissolution chemical is also described.

Abstract: A method for containing or removing contamination from a substrate includes applying a material such as a polyurea elastomer to the contaminated substrate. Preferably, the material sets in less than about 1 hour and is substantially unaffected by exposure to radiation. The contaminants can be contained or shielded on the substrate by the material to reduce exposure to the contaminants. In one preferred embodiment, this invention relates to the encapsulation of objects or surfaces to shield persons in the area from contamination. Alternatively, the material can be removed from the substrate to remove contaminants. Preferably, the material provides a Decontamination Factor of at least about 10. In another preferred embodiment, the material is applied hot to the contaminated substrate to increase its effectiveness in removing contaminants. The present method can also prevent contamination of an uncontaminated substrate.

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.

Abstract: A process for removing undesirable material such as a radioactive contaminant from an underlying material. A solution containing fluoroboric acid and a material which affects oxidation potential (Eh) is contacted with the undesirable material to cause its removal. The material is removed from the fluoroboric acid solution by contacting the solution with a cation exchange resin and fluoroboric acid is regenerated in situ for continuous removal of undesirable material.

Abstract: The present invention provides a method of decontaminating an article containing lead contaminated with radioactive material. The method includes contacting the article containing lead contaminated with radioactive material with a decontamination composition comprising about 0.01 to 5 percent, by weight, of a reductant, about 0.01 to 5 percent, by weight, of a compound selected from the group consisting of citric acid, alkali metal and ammonium salts of citric acid and mixtures thereof; 1 to 15 percent, by weight, of a compound selected from the group consisting of polyaminocarboxylic acid, alkali metal and ammonium salts of polyaminocarboxylic acid and the combination of a polyaminocarboxylic acid and a neutralizing compound and mixtures thereof; 0 to 1 percent, by weight, of a nonionic surfactant; 0 to 1 percent, by weight, of a dispersant; and 0 to 1 percent, by weight, of a corrosion inhibitor, and the balance water or other aqueous liquid.

Abstract: Soil including sand and clays contaminated with nuclear waste materials and/or ions of hazardous non-radioactive metals or metalloids are decontaminated by treating with anhydrous liquid ammonia alone or in combination with solvated electrons. Methods include removing ions of hazardous metals or metalloids by mixing with ammoniacal solutions to provide an ammoniacal liquid-containing product with coordination complexes. Methods also comprise concentrating contaminants, such as plutonium, uranium and thorium, for example, in the fines of soil and clay to yield residual soil products which are sufficiently free of contaminants to allow reclamation. Economics are improved over aqueous systems since ammonia can be recovered and recycled. By concentrating nuclear and nonnuclear wastes in soil fines space requirements ordinarily needed for storage of untreated soil and handling costs can be significantly reduced.

Abstract: A method to decontaminate radioactively contaminated metallic objects in which the objects are contacted with a non- radioactive, aqueous solution containing acetic acid. The metallic objects are in contact with the acid continuously or successively over several hours until the acid is completely stoichiometrically depleted. The concentration of the aqueous solution containing acetic acid is preferably approximately 0.3 Mol/l. These steps are repeated until the residual contamination of the metallic objects is beneath the desired target threshold of 0.37 Bq/cm.sup.2. The radioactive metallic oxides and metallic hydroxides in the aqueous stoichiometrically depleted solution are sedimented out, and the sludge is solidified with cement and subsequently decontaminated.

Abstract: Disclosed is a method for removing radioactive contaminants from metal surfaces by applying steam containing an inorganic acid and cerium IV. Cerium IV is applied to contaminated metal surfaces by introducing cerium IV in solution into a steam spray directed at contaminated metal surfaces. Cerium IV solution is converted to an essentially atomized or vapor phase by the steam.

Abstract: A method of decontaminating the surface of a body carrying radioactive contaminants which comprises treating the surface with a decontaminant comprising a solution of tetrafluoroboric acid HBF.sub.4, treating the resultant liquor comprising decontaminant and dissolved species removed from the body surface with a first chemical agent which on reacting with dissolved species yields insoluble compounds and regenerated decontaminant solution, and characterized in that the regenerated decontaminant solution is further treated to cause removal of the first chemical agent from the decontaminant solution.

Abstract: Soil including sand and clays contaminated with elemental mercury are decontaminated by forming slurries with anhydrous liquid ammonia. An ammoniacal liquid, such as anhydrous liquid ammonia facilitates decontamination by breaking up soil into fine slurries for releasing droplets of mercury metal. The high density of the mercury metal permits precipitation with larger soil particles and for recovery from soil particulates. Contaminated soils having mixed wastes comprising metallic mercury with organic compounds like PCBs are decontaminated first by slurring with anhydrous liquid ammonia to release droplets of mercury for coalescing and recovery. Solvated electrons are formed in the slurry in-situ by treating the slurry with an alkali metal or alkaline earth metal to reduce or degrade toxic organic compounds to more environmentally benign substances.

Abstract: A process for the treatment of material which is or is suspected to be contaminated with one or more actinides or compounds thereof, which process includes contacting the said material with a liquid medium which comprises an aqueous solution which is free of heavy metal ions (prior to use thereof) and comprises ingredients which are naturally degradable to non-toxic products with or without mild physical assistance such as heat or ultra-violet radiation, said solution comprising:(a) carbonated water;(b) a conditioning agent; and(c) a complexing agent which comprises the anion of a carboxylic acid having from 2 to 6 carbon atoms;wherein the said process is for treatment of solid organic wastes which are or are suspected to be contaminated with plutonium or compounds thereof with or without other hazardous contaminants and includes the steps of shredding the organic waste material, intimately mixing the shredded waste material with the said liquid medium thereby dissolving contaminants as complexes in said liqu

Abstract: A method and system for removing a surface layer contaminated with radioactive and/or hazardous material and subsequently treating the waste to remove contaminants and provide an essentially contaminant-free final effluent. The contaminated material is removed by blasting the surface with a pressurized stream of air and sodium bicarbonate abrasive media, and the media is dissolved in water subsequent to the blasing operation. The resulting waste is treated in a sequence of steps including adjustment of pH, aeration and separation into primarily solid and liquid phases by precipitation of solids, which are removed for appropriate disposal. The primarily liquid phase is successively passed through a particle filter, a granulated activated carbon filter and a polishing unit to produce the clean final effluent.

Abstract: A process for the decontamination of solid surfaces contaminated with radioactive or heavy metal species using a solution based on one or more non-persistent complexing agents, or for the chemical cleaning of steam generator sludge using such a solution, or for removing radioactive or heavy metal species from a solution using a combination of a one or more non-persistent complexing agents and a solid support, followed in each case by thermal or thermal-chemical treatment to decompose said non-persistent complexing agent. The preferred non-persistent complexing agents are hydroxamic acids, and the most preferred is acetohydroxamic acid.

Abstract: A method for removing radioactive barium sulphate from fluid carrying equipment includes immersing the equipment and scale in liquid nitrogen or other cyrogenic liquid, followed by immersing the equipment and scale in water or other aqueous solution, and subsequent impacting of the equipment and scale to remove the scale.

Abstract: A process for decontaminating radioactive material comprises the step of contacting the material with a dissolving composition to dissolve the contaminants in the material, said composition comprising a dilute solution of about 0.05 molar ethylene diamine tetraacetic acid, about 0.1 molar carbonate, about 10 grams per liter hydrogen peroxide and an effective amount of sodium hydroxide to adjust the pH of the composition to a pH from about 9 to about 11. Also included are the steps of separating the dissolving composition containing the dissolved contaminants from the contacted material and recovering dissolved contaminants from the dissolving composition that has been separated from the material. A composition for dissolving radioactive contaminants in a material, comprising a dilute solution having a basic pH and effective amounts of a chelating agent and a carbonate sufficient to dissolve radioactive contaminants is also provided.

Abstract: Applying shotblast or sandblast to a substance contaminated with radioactivity, cleaning the substance with a liquid, washing the grit of shotblast or sandblast with an organic solvent, filtering the resulting organic solvent, decontaminating the organic solvent itself by distilling the organic solvent filtered, and using this decontaminated solvent for washing said grit.

Abstract: A decontaminating apparatus for cleaning radioactive contaminated surfaces and recovering for disposal the contaminated material, including a first recovery unit comprising a vacuum creating source in association with a second recovery unit that filters and demists the vacuum recovered contaminated material, and a third recovery unit that initially vacuum recovers the contaminated material and separates the same into fluid and air borne contaminates. The second and third recovery units each having a critical mass control responsive to the volume of contaminated material vacuumed from the surface being decontaminated.