Joint solubility of PuF3 and UF4 in a melt of lithium, sodium, and potassium fluorides

The solubility of PuF3 and UF4 added jointly into a melt of the molar composition 46.5LiF–11.5NaF–42KF was studied in the temperature range 823–1073 K. Anhydrous PuF3 and UF4 were synthesized. The isothermal saturation method was used in studying the dissolution of pressed PuF3 and UF4 pellets in the melt in an inert (argon) atmosphere. The temperature dependences of the solubilities of jointly added PuF3 and UF4 in the LiF–NaF–KF melt of the chosen composition were determined. The solubilities of PuF3 and UF4 added into the LiF–NaF–KF melt jointly are lower than the solubilities of the same fluorides added separately.