The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 16, 1993
Filed:
Dec. 16, 1992
Thomas S Snyder, Oakmont, PA (US);
Laura J Ayers, Knoxville, TN (US);
Chuck A Cooney, Kingston, TN (US);
Gregory F Boris, Knoxville, TN (US);
Dwight F Goad, Kingston, TN (US);
Kevin D Robbins, Kingston, TN (US);
Darrell B Watkins, Harriman, TN (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
Technetium-contaminated nickel is decontaminated by electrolytically dissolving nickel having a gross beta activity of at least about 74 Bq in a sulfuric acid solution having a pH between about 0.5 and 2.0. The applied voltage is from 2.0 v/cell to 5.0 v/cell for dissolving the nickel and contaminants while cathodically producing hydrogen gas. Technetium (+4) species in the acid solution is oxidized to the technetium (+7) species. The pH of the technetium-containing acid solution is adjusted to between 2.5 to 4.5. Particulates in the acid solution are filtered from the solution for reducing the gross beta activity of the acid solution to less than about 50 Bq/gm. Radioactive ions (including technetium complexes) are sorbed in an anionic exchanger and a cationic exchanger for reducing the gross beta activity of the acid solution to less than about 20 Bq/gm. After verifying the gross beta activity of the acid solution, the acid solution is either recycled or charged to a electrowinning step. Acid solution having an activity of more than about 20 Bq/gm is recycled to upstream of the anion exchanger and the cationic exchanger. Acid solution having a gross beta activity of less than about 20 Bq/gm is charged to the electrowinning step. Nickel is plated at a voltage of about 2 v/cell to about 6 v/cell while oxygen gas is anodically generated. The pH of barren metal acid solution from the electrowinning step is reduced to less than about 2 and the barren metal acid solution is recycled for dissolving additional contaminated nickel.