Long-term evolution of plutonium waste-form candidates, with focus on radiation effects on dissolution behaviour.

点击翻译按钮获取中文摘要

Zirconolite ceramic and disposal MOX wasteforms pose a challenge to standard dissolution test protocols given their extremely low solubility. Hence, there is a need to develop methodologies to adequately test ceramic wasteform durability, for the purpose of comparison, as well as to develop a robust data set to demonstrate an adequate mechanistic understanding of product performance, and to quantitatively determine dissolution rates. In this context, there remain important but unresolved philosophical questions, such as: whether the radiation damage-induced crystalline to amorphous phase transition (or in the case of MOX, induction of oxygen vacancy defects) results in enhanced dissolution rates; whether neutron poisons are released at the same rate as U/Pu(Ce/Th) and; how alpha radiolysis of water influences the corrosion of U/Pu in zirconolite ceramic and disposal MOX wasteforms. There is an appreciation that development and optimisation of test methodologies should also look ahead to deployment against Pu prototype wasteforms within a glove box environment, and for applicability to disposal-MOX formulations. This PhD project will explore these aspects of plutonium waste form candidate ceramic dissolution, with emphasis on the role of radiation.