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

由于其极低的溶解度，锆石陶瓷和处理MOX废品对标准的溶解测试方案构成了挑战。因此，有必要开发方法来充分测试陶瓷废料的耐久性，以便进行比较，以及开发可靠的数据集，以证明对产品性能有充分的机械理解，并定量确定溶解速率。在这种背景下，仍然存在着重要但尚未解决的哲学问题，如：辐射损伤引起的晶态到非晶态的相变(或在MOX的情况下，引起氧空位缺陷)是否导致溶解速度增加；中子毒物的释放速度是否与U/Pu(Ce/Th)的释放速率相同；水的α辐射分解如何影响U/Pu在锆石陶瓷中的腐蚀和处理MOX废料。人们认识到，测试方法的开发和优化还应着眼于针对手套箱环境中的钚原型废纸进行部署，以及对Disposal-MOX配方的适用性。这个博士项目将探索这些方面的钚废物的候选陶瓷溶解，重点是辐射的作用。

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.