Innovation in the Design of Improved Actinide Selective Extractants Suitable for use in Large Scale Spent Nuclear Fuel Reprocessing

适用于大规模乏核燃料后处理的改进锕系元素选择性萃取剂的设计创新

基本信息

批准号：
EP/P004873/1
负责人：
Frank Lewis
金额：
$ 12.83万
依托单位：
Northumbria University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2017
资助国家：
英国
起止时间：
2017 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FP004873%2F1
关键词：
Innovation Design Improved Actinide Selective

项目摘要

A key challenge that needs to be overcome in spent nuclear fuel reprocessing is to separate the radiotoxic minor actinides from the non-radiotoxic lanthanides. Extracting and separating these elements from the lanthanides after the 'Plutonium and URanium EXtraction' (PUREX) process will reduce the long lived radiotoxicity of the remaining spent fuel and enable these elements to be rendered safe by transmutation (high energy neutron bombardment) or used as fuel in advanced GenerationIV reactors. This separation is critical because the lanthanides have higher neutron capture radii than the actinides and would thus prevent the neutron chain reaction that would render the actinides safe. Three families of N-donor ligand containing the 1,2,4-triazine moiety have been developed that can extract and separate the minor actinides from the lanthanides with very high selectivity. These are known as bistriazinylpyridines (BTPs), bistriazinylbipyridines (BTBPs) and bistriazinylphenanthrolines (BTPhens). However, whilst these ligands fulfill many of the requirements for use in a 'Selective ActiNide EXtraction' (SANEX) separation process, two main limitations remain to be overcome prior to industrial scale use:1. Their limited solubility range in solvents acceptable to the nuclear industry (typically less than 10 mM). 2. Their relatively slow rates of extraction.To the best of our knowledge, there has been no research on the exploration of other N-donor ligand families containing the crucial 1,2,4-triazine moiety. Furthermore, the application of an innovative approach to improving the above limitations has not previously been carried out. This research proposal aims to investigate new families of N-donor ligand based on the 1,2,4-triazine moiety for the selective extraction of actinides over lanthanides. This will advance the fields of spent nuclear fuel reprocessing and radioactive waste management, with the potential for the ligands to be used by the nuclear industry in future large-scale actinide-lanthanide separation processes that will underpin the current resurgence in nuclear energy. If successful, this proposed research would expand the scope of currently available ligands for use in the processing of spent nuclear fuel and provide one or more lead structures with improved solvent extraction properties suitable for future industrial use. The novelty of the proposed approach lies in (i) Synthesis of new ligand families that have never been explored previously for the separation of actinides from lanthanides. (ii) The application of an innovative approach to ligand design that addresses the two most critical shortcomings of existing 1,2,4-triazine based ligands; low solubilities and slow rates of extraction. This innovative approach is inspired by those aspects of drug discovery that specifically relate to solubility and polarity (which can influence surface concentration at an organic/aqueous interface and hence extraction kinetics). The research is timely because, after several decades of decline in the UK and worldwide, nuclear energy is experiencing a resurgence in fortunes (the 'nuclear renaissance') and several countries (including the UK) have announced plans for new reactor build. This means the volume of spent nuclear fuel will continue to increase in future. However, no process is currently available to render this material safe for geological disposal. Thus it is even more important to develop a feasible selective actinide extraction process in the near future. The project includes two academic collaborators who have extensive expertise in performing solvent extraction measurements on ligands using radionuclides, and developing novel selective actinide extraction processes. The project also includes one industrial collaborator who has expertise in the commercialization and exploitation of new technology and products, and who already markets a range of ligands to the global nuclear industry.

在用过的核燃料后处理中需要克服的一个关键挑战是将放射性毒性的小肌动剂与非放射性毒素的灯笼分开。在“ p和铀提取”过程之后，将这些元素从灯笼中提取和分离，将降低其余用过的燃料的长期存在的放射性毒性，并使这些元素能够通过trans变（高能量中子轰炸）或用作高级发电机中的燃料来确保这些元素。这种分离是至关重要的，因为灯笼的中子捕获半径比actinides更高，因此可以防止中子链反应使肌动剂安全。已经开发了三个含有1,2,4-三嗪部分的N-二酮配体家族，可以以非常高的选择性提取和将少量肌动剂与灯笼分开。这些被称为Bistriazinylpyridines（BTPS），二唑吡啶甲酰吡啶（BTBPS）和二苯二氨基苯基氨基氨基氨基氨基烷（BTPHENS）。但是，尽管这些配体满足了“选择性actinide提取”（SANEX）分离过程中使用的许多要求，但在工业规模使用之前仍有两个主要限制仍有两个主要限制：1。它们在核工业中可接受的溶剂中溶解度有限（通常小于10毫米）。 2。它们的提取率相对较慢。在我们的最佳知识中，没有关于探索其他N-Donor配体系列的研究，这些N-Donor配体系列包含至关重要的1,2,4-三嗪部分。此外，以前尚未实施创新方法来改善上述限制。这项研究建议旨在根据1,2,4-三嗪部分来调查N-谱系配体的新家族，以选择性地提取乙酰胺而不是灯笼。这将推动花费的核燃料再处理和放射性废物管理的领域，并有可能在未来的大型乙酰乙酰胺分离过程中被核工业使用，这将支持当前核能的复兴。如果成功的话，这项拟议的研究将扩大当前可用的配体的范围，用于处理用过的核燃料，并提供一种或多种铅结构，具有改进的溶剂提取性能，适合将来的工业用途。所提出的方法的新颖性在于（i）合成新的配体家庭，这些家族以前从未探索过actactinides与lanthanides分离。（ii）将创新方法应用于配体设计，该方法解决了现有的1,2,4-三嗪配体的两个最关键的缺点；低溶解度和提取速率缓慢。这种创新的方法的灵感来自与溶解度和极性有关的药物发现的那些方面（这可能影响有机/水性界面上的表面浓度，从而影响提取动力学）。这项研究之所以及时，是因为在英国和全球范围内的几十年下降之后，核能正在经历命运（“核文艺复兴”）的复兴，几个国家（包括英国）宣布了新反应堆建造的计划。这意味着将来的消费核燃料数量将继续增加。但是，目前尚无程序来使这种材料安全用于地质处置。因此，在不久的将来开发可行的选择性actinide提取过程更为重要。该项目包括两个学术合作者，他们在使用放射性核素对配体进行溶剂提取测量以及开发新颖的选择性actinide提取过程方面具有广泛的专业知识。该项目还包括一个工业合作者，他在新技术和产品的商业化和开发方面具有专业知识，并且已经向全球核工业销售了一系列配体。