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

钚废物候选形式的长期演变，重点关注辐射对溶解行为的影响。

• 批准号: 2597992
• 金额: --
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2597992
• 关键词: Long; term; evolution; plutonium; waste

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.

由于锆英石陶瓷和处置 MOX 废物的溶解度极低，因此对标准溶出测试方案提出了挑战。因此，需要开发方法来充分测试陶瓷废料的耐久性，以进行比较，并开发可靠的数据集来证明对产品性能的充分机械理解，并定量确定溶解速率。在这种情况下，仍然存在重要但尚未解决的哲学问题，例如：辐射损伤引起的结晶到非晶相变（或在 MOX 的情况下，诱导氧空位缺陷）是否会导致溶解速率提高？中子毒物的释放速度是否与 U/Pu(Ce/Th) 相同；水的 α 辐射分解如何影响锆英石陶瓷中 U/Pu 的腐蚀和处置 MOX 废物。人们认识到，测试方法的开发和优化还应着眼于在手套箱环境中针对 Pu 原型废物的部署，以及对处置 MOX 配方的适用性。该博士项目将探讨钚废物形成候选陶瓷溶解的这些方面，重点是辐射的作用。