je9b00933_si_001.pdf (235.19 kB)
Validity of the Simple Solution Concept for the Aqueous Quaternary System U(IV) Nitrate–U(VI) Nitrate–Nitric Acid–Water
journal contribution
posted on 2020-03-13, 21:44 authored by Valentin Dru, Gilles Bernier, Solenne Michaud, Philippe Marc, Christian SorelThis work focuses on the validity of the simple solution concept
of the uranium(IV) nitrate and uranium(VI) nitrate aqueous mixtures
through different means such as water activity or density measurements
using a simple solution approach. Since these two elements are mixed
together in the plutonium uranium redox extraction (PUREX) process
during the partitioning step, which separates uranium from plutonium,
the knowledge of behavior of this mixture will help in the modeling
of this process. This will allow a more precise code to be developed
and thus better modeling of the different components involved in the
PUREX process. Lately, thermodynamic codes are developed taking into
account deviation from ideality. These deviations from ideality are
estimated thanks to a solution theory. The one that will be used in
this paper is the simple solution approach, a simplification of the
McKay and Perring equation. The simple behavior of the uranium(IV)
and uranium(VI) mixture will be checked using different methods. The
precision of each method will then be discussed. This will be made
through the acquisition of water activity, density, and molality of
different solutions of uranium(IV) nitrate and uranium(VI) nitrate.