Abstract
Understanding the corrosion of nuclear waste glass is critical to predicting its safe disposal within a geological facility. The corrosion mechanisms and kinetics of the International Simple Glass, a simplified version of high-level nuclear waste glass, was shown to be significantly influenced by a high pH cement solution representative of disposal conditions. We provide the first microscopic characterisation of the porous, Zr-rich aluminoalkali-silica gel corrosion layer that was observed. Ca, Na and K from the cement solution were incorporated into the corrosion layer to charge compensate Si, Al and Zr species; the incorporation of Al was postulated to result in precipitation of an aluminosilicate-rich gel with large voids, facilitating rapid transport of species through the gel layer and significantly enhancing the corrosion rate. Precipitation of Al-containing zeolite and phyllosilicate phases was also observed, indicating that cementitious solutions may promote the detrimental ‘rate resumption’ stage of glass corrosion.
| Original language | English |
|---|---|
| Article number | 5 |
| Journal | npj Materials Degradation |
| Volume | 3 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2019 |
Funding
The UK research team are grateful to the Engineering and Physical Science Research Council for funding under grant awards EP/N017374/1 and EP/G037140/1. This research was performed, in part, at the MIDAS Facility, at the University of Sheffield, which was established with support from the Department of Energy and Climate Change. This project was co-financed by ONDRAF/NIRAS, the Belgian Agency for the Management of Radioactive Waste and Fissile Materials, as part of its program on the geological disposal of high-level and intermediate-level long-lived radioactive waste. The authors gratefully acknowledge the technical support from Ben Gielen. The portions of the research conducted at Oak Ridge National Laboratory (ORNL) were supported by the US Department of Energy’s Office of Environmental Management (EM) Tank Waste Management program. ORNL is operated by UT-Battelle, LLC for the US DOE under Contract No. DE-AC05-00OR22725.
