Development of a glass-encapsulated calcium phosphate wasteform for the immobilization of actinide and halide containing radioactive wastes from the pyrochemical reprocessing of plutonium metal
| Autor: | B.L. Metcalfe, Shirley K. Fong, I.W. Donald |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Materials science
Borosilicate glass Mechanical Engineering Fluorapatite Metals and Alloys chemistry.chemical_element Radioactive waste Plutonium Waste treatment Chemical engineering chemistry Mechanics of Materials visual_art Materials Chemistry visual_art.visual_art_medium Vitrification Ceramic Glass transition Nuclear chemistry |
| Zdroj: | Journal of Alloys and Compounds. :424-428 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2007.04.305 |
| Popis: | Chloride-containing radioactive wastes are generated during the pyrochemical reprocessing of Pu metal. Immobilization of these wastes in borosilicate glass or Synroc-type ceramics is not viable due to the very low solubility of chlorides in these hosts. Alternative wasteforms, including zeolites and direct vitrification in phosphate glasses, were therefore studied. However, the preferred option was to immobilize the waste in calcium phosphate ceramics, forming a number of stable mineral phases including chlorapatite, chloride-substituted fluorapatite and spodiosite. The immobilization process developed in this study involves a solid state process in which waste and host powders are reacted in air at temperatures in the range of 700–800 °C. The ceramic products obtained by this process are non-hygroscopic free-flowing powders that require encapsulation in glass to produce a monolithic wasteform suitable for storage and ultimate disposal. A suitable relatively low melting temperature phosphate-based glass was identified. Durability trials of both the ceramic powder and sintered glass-ceramic hybrid wasteform indicate that both the halides and actinide surrogate ions are satisfactorily immobilized. |
| Databáze: | OpenAIRE |
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