Structural Characterizations of Rare Earth-Rich Glasses for Nuclear Waste Immobilization

I. Bardez (1) , Daniel Caurant (1) , J.-L. Dussossoy , P. Loiseau (1) , C. Gervais (2) , F. Ribot (2) , D.R. Neuville , N. Baffier (1) , C. Fillet

1 LCMCP (site ENSCP) - Laboratoire de Chimie de la Matière Condensée de Paris (site ENSCP)
2 LCMCP (site Paris VI) - Laboratoire de Chimie de la Matière Condensée de Paris (site Paris VI)

New nuclear glass compositions, able to immobilize highly active liquid wastes arising from high burn-up UO2 fuel reprocessing, are being studied. Investigations are being performed on rare earth-rich glasses, known as durable matrices. After a preliminary study, a basic glass composition was selected (Glass A, wt. %) : 51.0 SiO2 – 8.5 B2O3 – 12.2 Na2O – 4.3 Al2O3 – 4.8 CaO – 3.2 ZrO2 – 16.0 Nd2O3. The aim of this study is to determine the local environment of the rare earth in this glass and its evolution according to neodymium. To achieve this objective, glasses were prepared from the baseline Glass A with variable neodymium oxide amounts (from 0 to 30 wt. % Nd2O3). By coupling characterization methods such as EXAFS (Extended X-Ray Absorption Fine Structure) spectroscopy at the neodymium LIII-edge, optical absorption spectroscopy, 11B, 27Al MAS-NMR and Raman spectroscopy, pieces of information on the rare earth surroundings in the glass were obtained.

Mots clés: glass; rare-earth; nuclear waste; EXAFS; neodymium; NMR

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Matériaux

I. Bardez, Daniel Caurant, J.-L. Dussossoy, P. Loiseau, C. Gervais, et al.. Structural Characterizations of Rare Earth-Rich Glasses for Nuclear Waste Immobilization. ATALANTE 2004 (advances for future nuclear fuel cycles), Jun 2004, Nîmes, France. ⟨hal-00177963⟩