A. Wilcox, “The Kinetic and Thermodynamic Properties of the Dissolution of Sodium Bimsuthate”, M.S. Thesis, Nuclear Engineering, Texas A&M University, College Station, TX (2018).
The development of a group actinide separation of U, Pu, Np, and Am could significantly simplify the closure of the nuclear fuel cycle, while reducing the amount of nuclear waste produced. To perform this group extraction the difficult separation of Am3+ from Cm3+ and the trivalent lanthanides must be addressed. Higher oxidation states of Am have been observed but require a high oxidizing potential to achieve. NaBiO3 has been shown to be capable of oxidation of Am(III)/Am(VI) in highly concentrated nitric acid and is known to be a cost effective and easily produced oxidizing agent. The slow dissolution kinetics of sodium bismuthate that have been observed, as well as its low solubility in nitric acid represent some concerns in adoption a process in which it is implemented. For this reason a thorough investigation of these properties as a function of nitric acid concentrations was undertaken. In addition, the effect of having other mental ions present in solution, like Cs+, Sr2+, Nd3+, Zr4+, Ce3+/4+, UO22+ on the dissolution behavior of sodium bismuthate was determined. Except for in the case of Sr2+ these metal ions were seen to reduce the solubility limit of sodium bismuthate to varying degrees, while each ion was also found to either have a neutral or positive effect on the dissolution rate.