Determination of the Bromley contributions to estimate the activity coefficient of neodymium electrolytes

International audienceIn the spent nuclear fuel reprocessing, solutions of actinides and lanthanides are concentrated and cannot be assumed as ideal ones. Activity coefficients have then to be calculated to take into account the deviation from ideality. The aim of this study is to determine new neodymium individual contributions for the calculation of activity coefficients using the Bromley method. A comparison with experimental data demonstrates that, with the contribution values of this work, the Bromley method can be successfully applied in ternary mixtures for the calculation of activity coefficients of neodymium compounds in aqueous solutions for ionic strengths up to 6 mol kg(-1) as claimed by Bromley. The simple method described in this paper can be used to correct or to determine the contributions of any other ion