Molecular dynamics simulation of ballistic effects in simplified nuclear waste glasses

Amreen Jan (1, 2) , Jean-Marc Delaye (3, 2) , S. Gin (4, 2) , Sebastien Kerisit (1)

1 PNNL - Pacific Northwest National Laboratory
2 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
3 LMPA - Laboratoire des Matériaux et Procédés Actifs
4 DPME - Département de recherche sur les Procédés et Matériaux pour les Environnements complexes

Ballistic effects in simple sodium borosilicate () and sodium alumino-borosilicate glasses () were investigated using molecular dynamics simulations. Specifically, the glasses were irradiated with heavy projectiles that caused atomic displacements by elastic collisions (displacement cascades) and progressively damaged the bulk glass. The accumulated pressure and internal energy inside the glass were found to saturate with deposited energy. Furthermore, structural analysis of the irradiated glasses revealed several important ballistic effects including a decrease in glass density, depolymerization of the borosilicate network, and increase in chemical mixing, short range and intermediate disorder. The magnitude of radiation damage was found to depend on the glass composition and, in general, alumino-borosilicate glasses were found to be slightly less damaged, after irradiation, as compared to borosilicate glasses.

Keywords: Molecular dynamics; borosilicate glasses; ballistic effects

Domains: Nuclear Experiment [nucl-ex]

Amreen Jan, Jean-Marc Delaye, S. Gin, Sebastien Kerisit. Molecular dynamics simulation of ballistic effects in simplified nuclear waste glasses. Journal of Non-Crystalline Solids, 2019, 505, pp.188-201. ⟨10.1016/j.jnoncrysol.2018.11.021⟩. ⟨cea-02510729⟩