An Evaluation of Single Phase Ceramic Formulations for Plutonium Disposition

Ceramics are promising potential hosts for the immobilization of actinide containing wastes. Work has been reported in the literature on multiphase systems, such as SYNROC [1], and on single phase systems such as pyrochlores [2] and zirconia [3], but assessment of the different waste-forms by direct comparison of literature data is not always easy due to the different processing and fabrication routes employed. In this study a potential range of different ceramic systems were investigated for plutonium disposition using the same processing scheme. Durable actinide containing minerals exist in nature and provided excellent target phases for the titanate, zirconate, silicate and phosphate based formulations examined here [4]. The Ce solid solution limits for each particular substitution mechanism were established and the processing parameters required to produce high quality ceramic specimens were optimised. Importantly, this was achieved within the constraints of a generic processing route suitable for fabrication of Pu bearing samples. (authors)