Developing technology and specifications for metakaolin-based geopolymers as robust and promising stabilisers for fuel debris removal

开发偏高岭土基地质聚合物的技术和规格，作为燃料碎片清除的强大且有前途的稳定剂

• 批准号: EP/Y029208/1
• 负责人: Brant Walkley
• 金额: $ 52.37万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FY029208%2F1
• 关键词: Developing; technology; specifications; metakaolin; based

Past and ongoing decommissioning and cleanup operations at both the TEPCO Fukushima Daiichi Nuclear Power Plant and Sellafield site has generated significant quantities of complex radioactive waste streams. This includes solid fuel debris waste fragments comprising mainly molten core concrete interaction products, which include a variety of materials such as metallic alloys, oxides, and silicates, and slurries and sediments containing fine particles or colloids, which are variously rich in metal carbonates, ferric oxide, and/or barium sulphate. New solidification and stabilisation methods are therefore urgently required to enable safe disposal of these waste streams.This project will use calcined clays as natural resources to engineer geopolymer binders, with and without boron as a neutron absorbent, to provide a robust and future-proof waste cementation matrix for long-term management and disposal of degraded fuels and contaminated wastes in Japan and the UK. This will broaden the formulation envelopes to increase waste loading and compatibility with wastes that cannot be effectively treated by conventional cementation.Geopolymer cements are produced via the chemical reaction between a source of alkalis (the "activator"), which is usually supplied as an aqueous solution, and a "precursor" powder that supplies silicate and aluminate for the reaction process. Geopolymer cements have been highlighted in technical and road-mapping publications in both the UK and Japan as offering very high potential for use in the treatment and disposal of diverse and problematic wastes. In particular, geopolymer production using calcined clays as the main precursor has been identified as offering the possibility for excellent technical performance as a waste conditioning matrix, controllable in the fresh and hardened states, while removing the reliance of the nuclear sector on conventional cementitious powders that will become increasingly scarce in the coming decades.We will identify and optimise geopolymer binder formulations that are robust to variations in the nature and characteristics of clay-derived and other precursors, including in terms of easy manufacturing (including desirable flow characteristics such as viscosity, yield stress, controlled thixotropy, and flow retention), radionuclide encapsulation (both cationic and anionic radionuclides), and encapsulation of complex waste streams such as solid waste fragments and slurries/sediments. This will underpin the use of geopolymers as a key part of the toolkit of cements that are needed to meet the remediation and decommissioning needs of the UK, Japan, and other countries worldwide. The project has strong bilateral UK and Japan links, incorporating expertise from both universities and the Japan Atomic Energy Agency (Japan) and Sellafield Ltd. (UK).

东京电力公司福岛第一核电站和塞拉菲尔德核电站过去和正在进行的退役和清理工作产生了大量复杂的放射性废流。这包括主要由熔核混凝土相互作用产物组成的固体燃料碎片，其中包括各种材料，如金属合金、氧化物和硅酸盐，以及含有细颗粒或胶体的泥浆和沉积物，这些泥浆和沉积物富含金属碳酸盐、三氧化二铁和/或硫酸钡。因此，迫切需要新的固化和稳定方法，以实现这些废流的安全处置。该项目将使用煅烧粘土作为自然资源，设计地质聚合物粘结剂，使用和不使用硼作为中子吸收剂，为日本和英国的降解燃料和受污染废物的长期管理和处置提供坚固且不受未来影响的废物胶结基质。这将扩大配方包络，以增加废物负载量，并与传统胶结无法有效处理的废物相容。土聚水泥是通过碱源(活化剂)与为反应过程提供硅酸盐和铝酸盐的“前驱体”粉末之间的化学反应而产生的。在英国和日本的技术和道路制图出版物中，地球聚合物水泥被强调为在处理和处置各种有问题的废物方面提供了非常高的潜力。特别是，使用煅烧粘土作为主要前体的地质聚合物生产已被确定为提供了作为废物调理基质的优秀技术性能的可能性，在新鲜和硬化状态下可控，同时消除了核部门对传统胶凝粉末的依赖，这些粉末在未来几十年将变得越来越稀缺。我们将确定和优化对粘土和其他前体的性质和特性变化具有很强耐受性的地质聚合物粘结剂配方，包括易于制造(包括所需的流动特性，如粘度、屈服应力、受控触变性和流动保持)、放射性核素封装(阳离子和阴离子放射性核素)、以及对固体废物碎片和泥浆/沉淀物等复杂废物流进行封装。这将支持使用地球聚合物作为水泥工具包的关键部分，以满足英国、日本和世界其他国家的补救和退役需求。该项目与英国和日本有很强的双边联系，吸收了两所大学以及日本原子能机构(日本)和赛拉菲尔德有限公司(英国)的专业知识。