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US 2006/0217584 A1Published application
Foam and gel methods for the decontamination of metallic surfaces
OwnerLuis Nunez, Michael Kaminskiinventors
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OwnerLuis Nunez, Michael Kaminskiinventors
Estimating the term…
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.
A method of decontaminating a radioactively contaminated metal oxide by contacting said radioactively contaminated metal oxide with a diphosphonic acid based gel for a time sufficient to dissolve the metal oxide by forming a radioactive diphosphonic acid complex and subsequentially decomposing the diphosphonic acid metal complex to produce a metal polymeric phosphate that can be converted to a waste form.
A method of decontaminating a radioactively contaminated surface including ferrous metal and non ferrous metal oxide values comprising prewetting the surface with reducing agents, complexing agent, or oxidizing agents then contacting the surface with diphosphonic acid based gel containing gelling agents for a sufficient time to dissolve the metal oxide by forming a radioactive diphosphonic acid metal complex and subsequently decomposing the radioactive diphosphonic acid metal complex to produced a poly phosphonic metal polymer that can be used as a waste form.
A method of decontaminating a radioactively contaminated surface including ferrous metal and non ferrous metal oxide values comprising contacting said radioactively contaminated surface with a mixture of reducing agents or oxidizing agents with diphosphonic acid based gel for a sufficient time to dissolve the metal oxide values by forming a radioactive diphosphonic acid metal complex and subsequently decomposing the radioactive diphosphonic acid metal complex to produced a polyphosphoric metal polymer that can be used as a waste form or combined with minimal physical or chemical treatment.
A method of decontaminating a radioactively contaminated metal oxide compromising contacting said radioactively contaminated metal oxide with a diphosphonic acid based foam solution for a time sufficient to dissolve the metal oxide by forming a radioactive diphosphonic acid complex and subsequentially decomposing the diphosphonic acid metal complex to produced a metal polymeric phosphate that can be converted physically or chemically to a waste form with minimal chemical additives.
A method of decontaminating a radioactively contaminated surface including ferrous metal and non ferrous metal oxide values comprising prewetting the surface with reducing agents, complexing agents or oxidizing agents then contacting surface with diphosphonic acid based foam containing foaming agents for a sufficient time to dissolve the metal oxide by forming a radioactive diphosphonic acid metal complex and subsequently decomposing the radioactive diphosphonic acid metal complex to produced a polyphosphate metal polymer that can be used as a waste form or combined with minimal physical or chemical treatment.
A method of decontaminating a radioactively contaminated surface including ferrous metal and non ferrous metal oxide values comprising contacting said radioactively contaminated surface with a mixture of reducing agents, complexing agents or oxiding agents with diphosphonic acid based foam for a sufficient time to dissolve the metal oxide values by forming a radioactive diphosphonic acid metal complex and subsequently decomposing the radioactive diphosphonic acid metal complex to produced a poly phosphonic metal polymer that can be used as a waste form or combined with minimal physical or chemical treatment.
A method of decontaminating a radioactively contaminated surface including ferrous metal and non-ferrous metal oxide values comprising contacting said radioactively contaminated surface with a mixture of a diphosphonic acid gel and a reducing agent, complexing agent, or an oxidizing agent for a time sufficient to dissolve the metal oxide and subsequently decomposing the radioactive diphosphonic acid metal complex to produce a polymer containing most of the radioactive values leaving a supernant solution containing low concentrations of radioactivity and/or metals, and removing the low concentrations of radioactivity and/or metals in a polishing step using selective magnetic particles.
A method of decontaminating a radioactively contaminated surface including ferrous metal and non-ferrous metal oxide values comprising contacting said radioactively contaminated surface with a mixture of a diphosphonic acid foam and a reducing agent, complexing agent, or an oxidizing agent for a time sufficient to dissolve the metal oxide and subsequently decomposing the radioactive diphosphonic acid metal complex to produce a polymer containing most of the radioactive values leaving a supernant solution containing low concentrations of radioactivity and/or metals, and removing the low concentrations of radioactivity and/or metals in a polishing step using selective magnetic particles.
A method of removing oxide from a surface containing one or more of ferrous oxide and non-ferrous oxide values comprising contacting said oxide with a diphosphonic acid gel and a reducing agent for a time sufficient to dissolve the oxide and forming a radioactive diphosphonic acid metal complex and subsequently decomposing the diphosphonic acid metal complex to produce a polymeric material containing most of the dissolved oxide values, and thereafter separating the decomposed diphosphonic acid solution from the polymeric material.
Dependencies are inferred from the claim text.