US EPA

1554250 

Journal Article 

Simultaneous spectrophotometric determination of uranium, nitric acid and nitrous acid by least-squares method in PUREX process 

Li, Li; Zhang, Hu; Ye, G 

2013 

Yes 

Journal of Radioanalytical and Nuclear Chemistry
ISSN: 0236-5731
EISSN: 1588-2780 

295 

1 

325-330 

10.1007/s10967-012-1833-8 

WOS:000312784200044 

Multi-wavelength linear regression spectrophotometry
combined with method of least squares for simultaneous determination of uranium, nitric acid and
nitrous acid in PUREX (Plutonium/URanium EXtraction) process was developed. The molar absorbance
matrix was calibrated with absorbance data measured in the wavelength range of 350-500 nm for a
series of standard solutions by linear least-squares regression. This method used information
from the absorption spectra of U(VI)-nitrous acid-nitric acid solutions to determine U(VI),
nitrous acid and nitric acid. In the range of 0.95-74.1 g/L U(VI), 5 x 10(-4)-2 x 10(-3) mol/L
nitrous acid and 3-5 mol/L aqueous nitric acid solution, the measuring precision for
determination of U(VI), nitrous acid and nitric acid was 0.46, 4.09, and 0.68 % respectively. In
the solution of 30 % TBP-kerosene, the measuring precision for determination of U(VI) and nitrous
acid was 0.42 and 4.2 % respectively in the range of 0.95-74.1 g/L U(VI) and 5 x 10(-4)-2x10(-3)
mol/L nitrous acid. The spectrophotometric method can be valuable for monitoring and controlling
of both species in PUREX process operation, thanks to its simplicity, efficiency and accuracy. 

Spectrophotometry; Uranium; Nitric acid; Nitrous acid; Least-squares regression