High-Level Waste Ceramics: Materials Considerations, Process Simulation, and Product Characterization

A ceramic is one of the alternatives for solidification and storage of high-level wastes (HLW). The procedure for developing a tailor-made ceramic with HLW ions fixed in mutually compatible, refractory and leach-resistant crystalline phases has been developed. Cold engineering-scale evaluation of an early ceramic formulation at Pacific Northwest Laboratories (PNL) has resulted in a product that is easily crystallized and has more than adequate thermal stability and leaching resistance. When combined with the continuous pelletizing and coatings processes developed at PNL, the results to date demonstrate that the tailor-made ceramic and the multibarrier waste forms are very promising advanced alternatives to glass as an HLW solid.