Solubility and Partitioning of Minor-actinides and Lanthanides in Alumino-borosilicate Nuclear Glass

We prepared a heterogeneous SiO2-B2O3-Na2O-Al2O3-CaO-La2O3 glass containing 11.76 wt.% AmO2. The composition of this heterogeneous material was determined from that of non-active glasses in which Am was fully substituted by Nd. For trivalent ion concentrations above the solubility limit, crystal formation occurred in the form of apatite-like silicates, this in both active and non-active glasses. Additions of Am+3 and Nd3+ led to depolymerization of the silicate network which is consistent with the modifier role expected from these cations. Thus, we can compare the incorporation mechanisms of neodymium and americium in the glassy network and within the apatite-like crystalline phases.