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Title: Foam and gel methods for the decontamination of metallic surfaces

Abstract

Decontamination of nuclear facilities is necessary to reduce the radiation field during normal operations and decommissioning of complex equipment. In this invention, we discuss gel and foam based diphosphonic acid (HEDPA) chemical solutions that are unique in that these solutions can be applied at room temperature; provide protection to the base metal for continued applications of the equipment; and reduce the final waste form production to one step. The HEDPA gels and foams are formulated with benign chemicals, including various solvents, such as ionic liquids and reducing and complexing agents such as hydroxamic acids, and formaldehyde sulfoxylate. Gel and foam based HEDPA processes allow for decontamination of difficult to reach surfaces that are unmanageable with traditional aqueous process methods. Also, the gel and foam components are optimized to maximize the dissolution rate and assist in the chemical transformation of the gel and foam to a stable waste form.

Inventors:
;
Publication Date:
Research Org.:
~Individually Owned Patent
Sponsoring Org.:
USDOE
OSTI Identifier:
1176080
Patent Number(s):
7,166,758
Application Number:
11/089,978
Assignee:
Nunez, Luis; Kaminski, Michael Donald OSTI
DOE Contract Number:
W-31-109-ENG-38
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY

Citation Formats

Nunez, Luis, and Kaminski, Michael Donald. Foam and gel methods for the decontamination of metallic surfaces. United States: N. p., 2007. Web.
Nunez, Luis, & Kaminski, Michael Donald. Foam and gel methods for the decontamination of metallic surfaces. United States.
Nunez, Luis, and Kaminski, Michael Donald. Tue . "Foam and gel methods for the decontamination of metallic surfaces". United States. doi:. https://www.osti.gov/servlets/purl/1176080.
@article{osti_1176080,
title = {Foam and gel methods for the decontamination of metallic surfaces},
author = {Nunez, Luis and Kaminski, Michael Donald},
abstractNote = {Decontamination of nuclear facilities is necessary to reduce the radiation field during normal operations and decommissioning of complex equipment. In this invention, we discuss gel and foam based diphosphonic acid (HEDPA) chemical solutions that are unique in that these solutions can be applied at room temperature; provide protection to the base metal for continued applications of the equipment; and reduce the final waste form production to one step. The HEDPA gels and foams are formulated with benign chemicals, including various solvents, such as ionic liquids and reducing and complexing agents such as hydroxamic acids, and formaldehyde sulfoxylate. Gel and foam based HEDPA processes allow for decontamination of difficult to reach surfaces that are unmanageable with traditional aqueous process methods. Also, the gel and foam components are optimized to maximize the dissolution rate and assist in the chemical transformation of the gel and foam to a stable waste form.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jan 23 00:00:00 EST 2007},
month = {Tue Jan 23 00:00:00 EST 2007}
}

Patent:

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  • A method of decontaminating a radioactively contaminated oxide on a surface. The radioactively contaminated oxide is contacted with a diphosphonic acid solution for a time sufficient to dissolve the oxide and subsequently produce a precipitate containing most of the radioactive values. Thereafter, the diphosphonic solution is separated from the precipitate. HEDPA is the preferred diphosphonic acid and oxidizing and reducing agents are used to initiate precipitation. SFS is the preferred reducing agent.
  • The present disclosure is directed to methods and compositions for boronizing metal and in particular ferrous surfaces. It has been discovered that if hydrocarbons are processed in metallic equipment which have been previously boronized, that coke formation and deposition which is commonly experienced at high temperatures can be minimized if not totally eliminated. The compositions utilized for this purpose are comprised of boron or boron compounds contained in an organic solvent or carrier together with specific activating materials.
  • Compositions and methods for decontaminating surfaces are disclosed. More specifically, compositions and methods for decontamination using a composition capable of generating a long lasting foam are disclosed. Compositions may include a surfactant and gelatin and have a pH of less than about 6. Such compositions may further include affinity-shifting chemicals. Methods may include decontaminating a contaminated surface with a composition or a foam that may include a surfactant and gelatin and have a pH of less than about 6.
  • The present invention provides an aqueous gel composition for removing actinide ions, lanthanide ions, fission product ions, or a combination thereof from a porous surface contaminated therewith. The composition comprises a polymer mixture comprising a gel forming cross-linked polymer and a linear polymer. The linear polymer is present at a concentration that is less than the concentration of the cross-linked polymer. The polymer mixture is at least about 95% hydrated with an aqueous solution comprising about 0.1 to about 3 percent by weight (wt %) of a multi-dentate organic acid chelating agent, and about 0.02 to about 0.6 molar (M)more » carbonate salt, to form a gel. When applied to a porous surface contaminated with actinide ions, lanthanide ions, and/or other fission product ions, the aqueous gel absorbs contaminating ions from the surface.« less
  • This patent describes an apparatus for use in qualifying materials that are used in the construction of nuclear reactors for decontamination by particular chemical decontamination processes. It comprises a primary circulation loop; a secondary flow loop.