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Title: Method for the recovery of actinide elements from nuclear reactor waste

Abstract

A process for partitioning and recovering actinide values from acidic waste solutions resulting from reprocessing of irradiated nuclear fuels by adding hydroxylammonium nitrate and hydrazine to the waste solution to adjust the valence of the neptunium and plutonium values in the solution to the +4 oxidation state, thus forming a feed solution and contacting the feed solution with an extractant of dihexoxyethyl phosphoric acid in an organic diluent whereby the actinide values, most of the rare earth values and some fission product values are taken up by the extractant. Separation is achieved by contacting the loaded extractant with two aqueous strip solutions, a nitric acid solution to selectively strip the americium, curium and rare earth values and an oxalate solution of tetramethylammonium hydrogen oxalate and oxalic acid or trimethylammonium hydrogen oxalate to selectively strip the neptunium, plutonium and fission product values. Uranium values remain in the extractant and may be recovered with a phosphoric acid strip. The neptunium and plutonium values are recovered from the oxalate by adding sufficient nitric acid to destroy the complexing ability of the oxalate, forming a second feed, and contacting the second feed with a second extractant of tricaprylmethylammonium nitrate in an inert diluent wherebymore » the neptunium and plutonium values are selectively extracted. The values are recovered from the extractant with formic acid.

Inventors:
 [1];  [2];  [3]
  1. Elmhurst, IL
  2. Woodridge, IL
  3. Clarendon Hills, IL
Issue Date:
Research Org.:
Argonne National Laboratory (ANL), Argonne, IL (United States)
OSTI Identifier:
863392
Patent Number(s):
4162230
Assignee:
United States of America as represented by United States (Washington, DC)
Patent Classifications (CPCs):
C - CHEMISTRY C01 - INORGANIC CHEMISTRY C01G - COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
C - CHEMISTRY C22 - METALLURGY C22B - PRODUCTION AND REFINING OF METALS
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; recovery; actinide; elements; nuclear; reactor; waste; process; partitioning; recovering; values; acidic; solutions; resulting; reprocessing; irradiated; fuels; adding; hydroxylammonium; nitrate; hydrazine; solution; adjust; valence; neptunium; plutonium; oxidation; forming; feed; contacting; extractant; dihexoxyethyl; phosphoric; acid; organic; diluent; whereby; rare; earth; fission; product; separation; achieved; loaded; aqueous; strip; nitric; selectively; americium; curium; oxalate; tetramethylammonium; hydrogen; oxalic; trimethylammonium; uranium; remain; recovered; sufficient; destroy; complexing; ability; tricaprylmethylammonium; inert; extracted; formic; adding sufficient; plutonium values; oxalic acid; nuclear fuels; actinide values; irradiated nuclear; feed solution; ammonium nitrate; fission product; acid solution; nitric acid; nuclear fuel; nuclear reactor; rare earth; phosphoric acid; waste solutions; waste solution; product values; uranium values; formic acid; reactor waste; solutions resulting; aqueous strip; actinide elements; selectively extract; strip solution; recovering actinide; earth values; hydroxylammonium nitrate; /252/423/976/

Citation Formats

Horwitz, E Philip, Delphin, Walter H, and Mason, George W. Method for the recovery of actinide elements from nuclear reactor waste. United States: N. p., 1979. Web.
Horwitz, E Philip, Delphin, Walter H, & Mason, George W. Method for the recovery of actinide elements from nuclear reactor waste. United States.
Horwitz, E Philip, Delphin, Walter H, and Mason, George W. Mon . "Method for the recovery of actinide elements from nuclear reactor waste". United States. https://www.osti.gov/servlets/purl/863392.
@article{osti_863392,
title = {Method for the recovery of actinide elements from nuclear reactor waste},
author = {Horwitz, E Philip and Delphin, Walter H and Mason, George W},
abstractNote = {A process for partitioning and recovering actinide values from acidic waste solutions resulting from reprocessing of irradiated nuclear fuels by adding hydroxylammonium nitrate and hydrazine to the waste solution to adjust the valence of the neptunium and plutonium values in the solution to the +4 oxidation state, thus forming a feed solution and contacting the feed solution with an extractant of dihexoxyethyl phosphoric acid in an organic diluent whereby the actinide values, most of the rare earth values and some fission product values are taken up by the extractant. Separation is achieved by contacting the loaded extractant with two aqueous strip solutions, a nitric acid solution to selectively strip the americium, curium and rare earth values and an oxalate solution of tetramethylammonium hydrogen oxalate and oxalic acid or trimethylammonium hydrogen oxalate to selectively strip the neptunium, plutonium and fission product values. Uranium values remain in the extractant and may be recovered with a phosphoric acid strip. The neptunium and plutonium values are recovered from the oxalate by adding sufficient nitric acid to destroy the complexing ability of the oxalate, forming a second feed, and contacting the second feed with a second extractant of tricaprylmethylammonium nitrate in an inert diluent whereby the neptunium and plutonium values are selectively extracted. The values are recovered from the extractant with formic acid.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1979},
month = {1}
}