| Through the fission process, which is necessary to produce electricity at a nuclear power plant, various types of nuclear waste are produced. These nuclear wastes are classified as high-level, transuranic, or low-level waste. All types of nuclear wastes need to be properly disposed. For high-level waste, the two methods in which disposal can be accomplished (for high-level radioactive waste) are to directly dispose of the waste or to reprocess the waste, vitrify it then dispose of it.;There are several plants throughout the world, which perform different types of reprocessing and vitrification processes. Among the various types of reprocessing processes are the purex, bismuth, redox, trigly, and the butex process. Although there are several processes, it is the purex process that is most widely used. The vitrification processes available are the two-stage and single-stage process, which are performed overseas, and the cold crucible, spray calcine, ceramic melter, and fluidized-bed calcination process, which are performed in the United States. Several solidification product alternatives for use in the vitrification process are calcine, supercalcine, borosilicate glass (the product of choice), phosphate glass, and glass ceramics. The requirements for a good solidification product are fission product content, irradiation stability, thermal stability, mechanical stability, and chemical stability.;Through reprocessing followed by vitrification, it is possible to recycle the usable portions of spent fuel and then properly dispose of the remaining nuclear wastes. |
