Amreen Jan1,N M Anoop Krishnan1
Indian Institute of Technology Delhi1
Amreen Jan1,N M Anoop Krishnan1
Indian Institute of Technology Delhi1
Confinement of radionuclides in borosilicate glass matrix is subject to the durability of vitrified nuclear waste glass in the aqueous medium on the geological time scales under repository conditions. It is now well accepted that under the aqueous condition there is a formation of a hydrated gel layer which is expected to play a significant role. However, the properties of this gel layer are not well understood yet. In this work hydrated gels are obtained from a series of pristine and irradiated borosilicate glasses. These gels are then aged at a temperature, of 2000K. It is observed that, indeed, there is a difference in the properties (connectivity, short and medium-range order) of aged gels formed from pristine and irradiated glass. Aging had a significant effect on the irradiated gels as compared to gels obtained from pristine glasses. Further, the role of medium-range order on the mobility of water is studied and it is observed how different ring distributions (pristine and irradiated) upon aging manifest similarly. mean rings size decrease in pristine gel and its increase in irradiated gel leads to a decrease in mobility of water across the gel upon aging.