Neutron diffraction study of sodium borosilicate waste glasses containing uranium

• Published in: Journal of non-crystalline solids Vol. 353; no. 18; pp. 1941 - 1945
• Main Authors: Fábián, M., Sváb, E., Mészáros, Gy, Révay, Zs, Veress, E.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 15.06.2007; Elsevier
• Subjects: Borosilicates; Condensed matter: structure, mechanical and thermal properties; Diffraction and scattering measurements; Disordered solids; Exact sciences and technology; Glasses; Medium-range order; Modeling and simulation; Monte Carlo simulations; Neutron diffraction/scattering; Oxide glasses; Physics; Short-range order; Structure; Structure of solids and liquids; crystallography; Borosilicates; Neutron diffraction/scattering; Modeling and simulation; Monte Carlo simulations; Diffraction and scattering measurements; Short-range order; Oxide glasses; 61.12.Ld; 61.43.Bn; Structure; 61.43.Fs; Medium-range order; Coordination number; Sodium oxides; Structure factors; Neutron diffraction; Medium range order; Liquid state quenching; Glass structure; Borosilicate glass; Uranium oxides; Zirconium oxides; Barium oxides; Modelling; Pair correlation function; Radioactive wastes; Reverse Monte Carlo method; Neutron diffusion; Silicon oxides; Application
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2007.02.021

The effect of uranium oxide on the structure of sodium borosilicate host glasses has been studied by neutron diffraction. The samples were prepared by quenching the melted mixtures of composition 70 wt% [(65 − x)SiO 2 · xB 2O 3 · 25Na 2O · 5BaO · 5ZrO 2] + 30 wt% UO 3 with x = 5, 10 and 15 mol%. It was found, that the U-loaded glasses posses good glass and hydrolytic stability. An enhanced probability for inter-mediate atomic correlations at around 4.8 Å has been established. The RMC simulation of the neutron diffraction data is consistent with a model where the uranium ions are incorporated into interstitial voids in the essentially unmodified network structure of the starting host glass. The U–O atomic pair correlation functions show a sharp peak at around 1.7 Å, and several farther distinct peaks are at 2.8, 3.6 and 4.1 Å. The uranium ions are coordinated by six oxygen atoms in the 1.6–3.4 Å interval.