Oxidation of Pu(III) by nitric acid in tri-n-butyl phosphate solutions. Part I. Kinetics of the reaction and its effect on plutonium losses in countercurrent liquid-liquid extraction

Journal Article · Mon Mar 01 00:00:00 EST 1982 · Nucl. Technol.; (United States)

OSTI ID:7178643

Sze, Y K; Clegg, L G; Gerwing, A F; Grant, G R

Oxidation of Pu(III) in tri-n-butyl phosphate solutions containing nitric acid has been studied by ultraviolet/visible spectrophotometry. The concentrations of Pu(IV) and nitrous acid (HNO/sub 2/), one of the reaction intermediates/products, were monitored. An autocatalytic reaction mechanism is proposed in which a small amount of HNO/sub 2/ is generated during an induction period. It then catalyzes the reaction by reacting with nitric acid to produce NO/sub 2/, which oxidizes Pu(III) in the rate-determining step. It is suggested a nitritoplutonium(IV) complex is formed that finally reacts with nitric acid to form more HNO/sub 2/. Reaction rates, measured under conditions similar to those encountered in a solvent extraction contactor, indicate that the reaction proceeds rapidly at concentrations of HNO/sub 3/ greater than about 0.2 M in the organic solutions, and it is responsible for plutonium losses often observed in solvent extraction operations.

• Research Organization: Atomic Energy of Canada Limited Whiteshell Nuclear Research Establishment Pinawa, Manitoba, ROE ILO
• OSTI ID: 7178643
• Journal Information: Nucl. Technol.; (United States), Vol. 56:3
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
NITRIC ACID
CATALYTIC EFFECTS
NITROUS ACID
PLUTONIUM
CHEMICAL REACTION KINETICS
OXIDATION
SOLVENT EXTRACTION
CATALYSIS
LOSSES
NITRITES
NITROGEN DIOXIDE
ORGANIC SOLVENTS
PLUTONIUM COMPLEXES
PLUTONIUM RECYCLE
PROCESS SOLUTIONS
REACTION INTERMEDIATES
SPECTROPHOTOMETRY
TBP
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA
ACTINIDE COMPLEXES
ACTINIDES
BUTYL PHOSPHATES
CHALCOGENIDES
CHEMICAL REACTIONS
COMPLEXES
DISPERSIONS
ELEMENTS
ESTERS
EXTRACTION
FUEL CYCLE
HYDROGEN COMPOUNDS
INORGANIC ACIDS
KINETICS
METALS
MIXTURES
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOSPHORIC ACID ESTERS
REACTION KINETICS
SEPARATION PROCESSES
SOLUTIONS
SOLVENTS
SPECTRA
TRANSURANIUM COMPLEXES
TRANSURANIUM ELEMENTS
050800* - Nuclear Fuels- Spent Fuels Reprocessing
400702 - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials
400105 - Separation Procedures