Recrystallization of 223 Ra with barium sulfate

In this work, the kinetics of barium sulfate recrystallization has been studied in acidic 0.01 mol dm −3 sodium sulfate solution using 223 Ra and 133 Ba tracers at very low total radium concentration, i.e. less than 10 −13 mol dm −3 . It was found that the system follows the homogeneous recrystallization model and that recrystallization rates, inferred by the decrease of 223 Ra and 133 Ba in the aqueous solution, are fast. Therefore, even at very low concentrations, below the solubility limit, radium will be retained by barium sulfate—a mineral present in the deep underground repository.