Settling of Spinel in A High-Level Waste Glass Melter

Hrma, Pavel ; Schill, Pert ; Nemec, Lubomir

Glass Service, LTD (United States)

关键词: Mixtures;    Radioactive Wastes;    Spinel;    Vitrification;    Chromium;   

DOI  :  10.2172/791850
RP-ID  :  DOE/ER/45739
RP-ID  :  FG07-98ER45739
RP-ID  :  791850

美国|英语

来源: UNT Digital Library

【 摘 要 】

High-level nuclear waste is being vitrified, i.e., converted to a durable glass that can be stored in a safe repository for hundreds of thousands of years. Waste vitrification is accomplished in reactors call melters to which the waste is charged together with glass-forming additives. The mixture is electrically heated to a temperature as high as 1150 degree C (or even higher in advanced melters) to create a melt that becomes glass on cooling. This process is slow and expensive. Moreover, the melters that are currently in use or are going to be used in the U.S. are sensitive to clogging and thus cannot process melt in which solid particles are suspended. These particles settle and gradually accumulate on the melter bottom. Such particles, most often small crystals of spinel ( a mineral containing iron, nickel, chromium, and other minor oxides), inevitably occurred in the melt when the content of the waste in the glass (called waste loading) increases above a certain limit. To avoid the presence of solid particles in the melter, the waste loading is kept rather low, in average 15% lower than in glass formulated for more robust melters.