The Effect of Heavy Ion Irradiation on the Forward Dissolution Rate of Borosilicate Glasses Studied in Situ and Real Time by Fluid-Cell Raman Spectroscopy

• Published in: Materials 2019-05, Vol.12 (9), p.1480
• Main Authors: Lönartz, Mara Iris, Dohmen, Lars, Lenting, Christoph, Trautmann, Christina, Lang, Maik, Geisler, Thorsten
• Format: Article
• Language: English
• Subjects: Borosilicate glass; borosilicate glass corrosion; Coordination numbers; Corrosion; Corrosion cell; Depolymerization; Dissolution; Experiments; forward dissolution rate; Geological time; Geology; heavy ion irradiation; Heavy ions; Impact damage; in situ fluid-cell Raman spectroscopy; Ion irradiation; Laboratories; MATERIALS SCIENCE; Nuclear energy; Nuclear fuels; NUCLEAR PHYSICS AND RADIATION PHYSICS; Nuclear power plants; Radiation damage; Radioactive wastes; Raman spectroscopy; Real time; Reprocessing; Silica glass; Silicon dioxide; Sodium bicarbonate; Spectrum analysis; Spent nuclear fuels; Stability analysis; Structural damage
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma12091480

Borosilicate glasses are the favored material for immobilization of high-level nuclear waste (HLW) from the reprocessing of spent fuel used in nuclear power plants. To assess the long-term stability of nuclear waste glasses, it is crucial to understand how self-irradiation affects the structural state of the glass and influences its dissolution behavior. In this study, we focus on the effect of heavy ion irradiation on the forward dissolution rate of a non-radioactive ternary borosilicate glass. To create extended radiation defects, the glass was subjected to heavy ion irradiation using Au ions that penetrated ~50 µm deep into the glass. The structural damage was characterized by Raman spectroscopy, revealing a significant depolymerization of the silicate and borate network in the irradiated glass and a reduction of the average boron coordination number. Real time, in situ fluid-cell Raman spectroscopic corrosion experiments were performed with the irradiated glass in a silica-undersaturated, 0.5 M NaHCO solution at temperatures between 80 and 85 °C (initial pH = 7.1). The time- and space-resolved in situ Raman data revealed a 3.7 ± 0.5 times increased forward dissolution rate for the irradiated glass compared to the non-irradiated glass, demonstrating a significant impact of irradiation-induced structural damage on the dissolution kinetics.