Fundamental Chemistry of U and Pu in the TBP-Dodecane-Nitric Acid System

Authors

Kenneth Czerwinski, University of Nevada, Las VegasFollow
Byron Bennett, University of Nevada, Las Vegas

Document Type

Annual Report

Publication Date

2005

First page number:

56

Last page number:

57

Abstract

The research objectives of this project are as follows:

• To determine the influence of nitrate on the speciation of U and Pu in the TBP-dodecane-nitric acid system. The aqueous and organic speciation of U and Pu are examined as a function of the nitric acid concentration, nitrate concentration (by the addition of NaNO₃), actinide ion concentration, temperature, and time.
• To determine the speciation of U and Pu with AHA in the presence and absence of TBP-dodecane organic phase. The aqueous and organic speciation of U and Pu are evaluated as a function of AHA concentration, metal ion concentration, metal ion redox state, pH, and temperature. Experiments will initially examine the aqueous phase then examine the two phase system.
• To incorporate thermodynamic and kinetic data into existing modeling codes. The following experimental techniques are used in the evaluation of U and Pu speciation: UV-Visible spectroscopy, Time resolved laser fluorescence spectroscopy, NMR spectroscopy, IR spectroscopy, Raman spectroscopy, Titrations, ICP-MS, ICP-AES, XAFS, and Electrochemical. Initial experiments are performed with UO₂²⁺. The initial results obtained with UO₂²⁺ are the basis for further experiments with Pu. In extraction experiments, the aqueous and organic phases are equal volumes and range from 0.5 mL to 5.0 mL. The actinide ion concentration varies from mmol/L to the mmol/ L range. Nitrate concentrate varies from the concentration due to nitric acid by the addition of NaNO₃. The nitric acid concentration varies from 14 M to the pH range in experiments with AHA. The temperature varies from 20 °C to 80 °C. The results will be used to determine Gibbs free energy.

Keywords

Nitric acid; Plutonium; Radioactive wastes – Purification; Separation (Technology); Speciation (Chemistry); Tributyl phosphate; Uranium

Controlled Subject

Nitric acid; Radioactive wastes--Purification; Tributyl phosphate

Disciplines

Analytical Chemistry | Chemistry | Oil, Gas, and Energy | Physical Chemistry | Radiochemistry

File Format

pdf

File Size

133 KB

Language

English

Rights

COPYRIGHT UNDETERMINED. For more information about this rights statement, please visit http://rightsstatements.org/vocab/UND/1.0/

Repository Citation

Czerwinski, K., Bennett, B. (2005). Fundamental Chemistry of U and Pu in the TBP-Dodecane-Nitric Acid System. 56-57.
Available at: https://digitalscholarship.unlv.edu/hrc_trp_separations/90