The long-term evolution of candidate Pu wasteforms as a function of groundwater composition

候选Pu废物形态随地下水成分变化的长期演化

• 批准号: 2570862
• 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: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2570862
• 关键词: long; term; evolution; candidate; Pu

Research and development is currently being undertaken to underpin a Nuclear Decommissioning Authority recommendation to Government in 2025 regarding the preferred re-use / disposal option for the UK's civil stockpile of separated plutonium. This research, part-funded by Radioactive Waste Management Limited, aims to build underpinning science for the decision about which disposal option is preferred for the part of the plutonium inventory that cannot be re-used, or the whole inventory, if plutonium is declared a waste in the future. This PhD project aims to quantify the dissolution kinetics and mechanisms of two candidate Pu-wasteform materials - disposal MOX [(U,Pu)O2] and zirconolite ceramics (e.g. CaZr0.8Ce0.2Ti2O7) - as a function of varying groundwater composition. The project will use batch, flow-through and surface-sensitive techniques to rapidly (within days to months), and precisely, quantify the effect of pH, Eh and ionic strength on the dissolution rates of Pu surrogates (Th and Ce), U and neutron poisons (e.g. Gd, Hf). Dissolution in synthetic groundwater solutions, backfill pore water, under oxic and anoxic conditions, will also be investigated using these techniques.

目前正在进行研究和开发，以支持核退役管理局在2025年向政府提出的关于联合王国分离钚民用储存的首选再利用/处置方案的建议。这项研究的部分资金由放射性废物管理有限公司提供，旨在建立基础科学，以便决定如果钚在未来被宣布为废物，对于不能再利用的钚库存部分或整个库存，哪种处置方案是首选。这个博士项目的目的是量化的溶解动力学和机制的两个候选人钚废物材料-处置MOX [（U，钚）O2]和锆英石陶瓷（如CaZr0.8Ce0.2Ti2O7）-作为不同的地下水成分的函数。该项目将使用批量、流通和表面敏感技术，快速（在几天到几个月内）、精确地量化pH、Eh和离子强度对钚替代物（Th和Ce）、铀和中子毒物（例如Gd、Hf）溶解速率的影响。溶解在合成地下水溶液，回填孔隙水，在好氧和缺氧条件下，也将使用这些技术进行调查。