Powder Processing for Hot-Isostatic Pressing of Nuclear Waste

The UK at present holds a substantial stockpile of civilian-owned plutonium dioxide, which recently has been proposed to be predominantly reused as MOX fuel. However, a significant proportion will not be suitable for this use and will need to be immobilized, with the main focus being on ceramic immobilization, using a zirconolite-based system manufactured using hot isostatic pressing. Key to this work has been the reduction of secondary wastes, such as lubricants, which can have an impact on the final wasteform, whilst at the same time optimize the final product formation. This presentation will examine the options for dry mixing, using lubricants that are both compatible with the process and the final zirconolite wasteform. Results from analysis of the final products using techniques such as X-ray powder diffraction, electron microscopy, and relative density will be shown, indicating the success of the work in being able to use solid lubricants.