Evolution of nuclear glass structure under α-irradiation

The French nuclear glass is intended for the long-time storage of high-level nuclear wastes. The disintegration of radioelements induces modifications of the glass structure which could deteriorate the efficiency of the confinement. We have focused our study on the effects from x-decay processes (alpha particles and recoil nuclei) in two simplified alumino-borosilicate glasses which contain the major constituents of French light water containment glass. The alpha-decay processes were simulated by external irradiations at room temperature with 1.0 MeV He+ or 2.1 MeV Kr3+ so as to exhibit the differences between effects produced by ct particles and by recoil nuclei. Micro-Raman spectroscopy has been used to investigate the evolution of the glass under rx-irradiation at a microstructural level through modifications of the network vibration bands. We have used nanoindentation to show the changes in macroscopic properties and the Molecular Dynamics (MD) method to observe the effect of a cascade at the atomic scale. (C) 2000 Elsevier Science B.V. All rights reserved.