# Leaching studies on borosilicate glasses for the immobilization of high-level radioactive waste in the pellet form subjected to aggressive test conditions

Authors
• 1 Bhabha Atomic Research Centre, Waste Management Division, Mumbai, 400085, India , Mumbai (India)
• 2 Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India , Mumbai (India)
• 3 Bhabha Atomic Research Centre, Chemistry Division, Mumbai, 400085, India , Mumbai (India)
Type
Published Article
Journal
Bulletin of Materials Science
Publisher
Springer-Verlag
Publication Date
Jun 28, 2019
Volume
42
Issue
5
Identifiers
DOI: 10.1007/s12034-019-1900-7
Source
Springer Nature
Keywords
Pellet leaching and associated thermal and structural changes of sodium borosilicate (NBS) glass, used for the immobilization of high-level radioactive liquid waste, subjected to aggressive test conditions have been compared with international simple glass (ISG) subjected to the same leaching conditions. The crystalline phase getting separated out from NBS glass is found to be different for pellets and powder leaching experiments and this has been explained based on the difference in the extent of leaching occurring with glass samples in the two experiments. Based on Fourier transform infrared studies, it is inferred that, unlike in the ISG sample, Si–O–Si/B structural units become more ordered with the leaching in the case of NBS glass, and this is attributed to the partial network destruction occurring with NBS glass and crystallization of the SiO2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {SiO}_{2}$$\end{document} phase from the glass matrix. Both the NBS glass and ISG sample show L-centre emission and the emission intensity remained unaffected with leaching, confirming that the local environment around non-bridging oxygen atoms in the NBS glass and ISG sample are unaffected and leaching occurs through network dissolution.