Novel waste forms

During the 1970s, particularly in the United States, a wide variety of candidate waste forms were considered for the incorporation and isolation of the high-level nuclear waste (Hench et al. 1984). These waste forms covered the full range of materials, from novel glass structures (e.g., stuffed porous silica glass matrix) to low-temperature materials (e.g., hydroxylated ceramics). In addition to the diversity in the types of materials, they represented combination of materials (e.g., glass marbles coated with metal or pyrolytic carbon) which provided for the multibarrier isolation of the radionuclides. Support for these waste forms was limited in both the time and the funds that were invested in their development. Thus, in some instances these waste forms were only ideas with little of the supporting data that are required for their complete evaluation. In general, there are little of the extensive data on corrosion mechanism, radiation effects, mechanical properties and large-scale production technology that has characterized the waste forms described in the previous chapters. After a several year period of review by numerous panels and individuals most of the support for the development of these alternative waste forms had ended by the early 1980s. The author was not directly involved in the development of any of these waste forms, but did serve on several of the panels that reviewed the relative merits of a number of the waste forms discussed in this chapter. The purpose of this article is to at least mention some of the excellent ideas that grew out of the work and competition between alternative waste forms in the late 1970s