| Abstract Scope |
The vitrification of high-level waste is challenged by the possible buildup of spinel crystals [(Fe, Ni, Mn, Zn)(Fe, Cr)2O4] in the glass discharge riser of Joule-heated ceramic melters during idle periods. This possibility is exacerbated by the current melter design, as temperatures of the melt pool are lowest near the region of the discharge spouts. While these crystals do not compromise glass durability, their accumulation can obstruct the discharge riser, hindering the flow of molten glass into storage canisters. Presently, to prevent crystal buildup, glass formulations are constrained by the liquidus temperature where the equilibrium spinel crystal fraction is 1 vol% (generally below 950°C). This restriction significantly reduces the waste loading capacity of the canisters, increasing both the cost and duration of the vitrification process. This study aims to explore the feasibility of increasing the crystal fraction without causing blockages in the pour spout. |