NEODYMIUM PARTITIONING IN ZIRCONOLITE-BASED GLASS-CERAMICS DESIGNED FOR MINOR ACTINIDES IMMOBILIZATION

P. Loiseau (1) , Daniel Caurant (1) , N. Baffier (1) , Catherine Fillet

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

This study deals with glass-ceramic matrices designed for the conditionning of minor actinides, in which zirconolite crystals (CaZrTi2O7) are homogeneously dispersed in a residual glassy matrix. Good immobilization performances require a high enrichment of actinides in the crystalline phase (double containment principle). Glass-ceramics are obtained by controlled devitrification of an aluminosilicate parent glass containing large amounts of TiO2 and ZrO2. Neodymium was selected to simulate the trivalent minor actinides. Crystallization was performed at 1200°C for various Nd2O3 contents (0 - 10 wt. %). In all cases, zirconolite crystallization is obtained in the bulk of glass-ceramics. The evolution of Nd3+ location between the crystals and the residual glass was followed by electron spin resonance and optical absorption. Both techniques demonstrate that neodymium is partly incorporated in zirconolite crystals. Moreover, total Nd2O3 content in parent glass has a strong effect on Nd3+ ions distribution.

Mots clés: minor actinides; neodymium; glass-ceramics; zirconolite; nuclear waste

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

P. Loiseau, Daniel Caurant, N. Baffier, Catherine Fillet. NEODYMIUM PARTITIONING IN ZIRCONOLITE-BASED GLASS-CERAMICS DESIGNED FOR MINOR ACTINIDES IMMOBILIZATION. Atalante 2000 (les recherches scientifiques sur l'aval du cycle pour le 21ème siècle), Oct 2000, Avignon, France. ⟨hal-00177950⟩