Radioactive waste forms

Lutze, W., Radioactive Waste Forms for the Future, Lutze, W. and Ewing, R. C., Eds., North-Holland, Amsterdam, 1988, 10, 133. 

Petit, J.C. (1992). Natural analogs for the design and performance assessment of radioactive-waste forms - a review. Journal of Geochemical Exploration 46 1-33. 

Harker, A. B. 1988. Tailored ceramics. In Lutze, W. Ewing, R. C. (eds) Radioactive Waste Form for the Future. Elsevier Science Publishers B.V., Amsterdam, 335-392. 

Ewing, R. C. 1979. Natural glasses analogues for radioactive waste forms. In McCarthy, G. J. (ed) Scientific Basis for Nuclear Waste Management I. Plenum Publishing Corp., New York, 57-68. 

Release rate data for radionuclides from fully radioactive waste forms are needed to evaluate the safety of nuclear waste glass. Presently, contact with water is considered the most important release path therefore, the release properties of waste glass in water are of primary concern. 

Release rate data from actual radioactive waste forms is needed to evaluate the safety of emplacing nuclear wastes in geologic media. However, in addition to waste form development studies, such as the leach test just described, a comprehensive program was started to obtain release data from candidate waste forms for geologic disposal. 

L. L. Hench, Leaching of Glass, Workshop on Ceramic and Glass Radioactive Waste Forms, Germantown, MD, January 1977. 

Method for Determining Leach Rates of Simulated Radioactive Waste Forms... 

Leaching onto Ion-Exchange Resins. A more sophisticated procedure for determining leachabilities of radioactive waste forms has been developed(7). Flowing deionized water is continuously circulated across the sample surface and then through ion-exchange resins where the leached ions are adsorbed. The adsorbed ions are subsequently eluted from the resin columns for atomic absorption analyses. Leachabilities measured by this procedure are claimed to be lower and more consistent than those made in stagnant water in the absence of continuous ionic control (7 ). 

The preparation, composition, structure and leaching characteristics of a crystalline, ceramic radioactive waste form have been discussed, and where applicable, compared with vitrified waste forms. The inorganic ion exchange materials used such as sodium titanate were prepared from the corresponding metal alkoxide. The alkoxides were reacted in methanol with a base containing the desired exchangeable cation and the final powder form was produced by hydrolysis in an acetone-water mixture followed by vacuum drying the precipitate at ambient temperature. 

Hartmann, T. Paviet-Hartmann, P. Rubin, J. B. Fitzsimmons, M. R. Sickafus, K. E. The Effect of Supercritical Carbon Dioxide Treatment on the Leachability and Structure of Cemented Radioactive Waste-Forms. Waste Manage. 1999, 19, 355-361. 

Waste form leach rates in a geologic repository will be affected by unknown water flow rates and by extensive cracking of the waste form monolith. An understanding of these effects is important in predicting the geochemical behavior of disposed radioactive waste forms over the full range of possible scenarios. The dependence of the waste form source term on the rate of renewal of aqueous solution is first established for the simple but important case of solubility-limited network dissolution control. 

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