Computational Design of Graphene-Based Materials for Challenging Nuclear Decommissioning Applications

核燃料循环（核燃料后处理、研发和能源生产）中使用的设施的安全退役是英国面临的一项重大社会经济挑战，预计未来120年的总成本将达到1200亿英镑。退役过程将产生大量具有放射性的水基废物（流出物），必须加以处理。除了与目前用于处理污水的材料和工艺相关的一些具体挑战外，随着退役活动的加快，在不久的将来可能会出现许多新的挑战。克服这些挑战对于建立公众对放射性废物管理的信心以及支持联合王国的长期能源战略至关重要。氧化石墨烯是石墨烯的衍生物，具有高氧含量，具有已在其他领域（例如脱盐）中证明的特殊性能，并且可能能够克服目前用于污水处理的材料所面临的限制。氧化石墨烯可以两种不同的方式用于处理废水。首先，可以将氧化石墨烯薄片添加到流出物中并用于直接结合放射性物质（吸附）。或者，可以使用由单个氧化石墨烯薄片制成的半透膜来筛选放射性物质（过滤）。在这个创新而雄心勃勃的项目中，将使用计算机模拟领导的方法来开发支持氧化石墨烯在核污水处理中使用的科学。首先，新的氧化石墨烯“粗粒度”模型的开发将显着延长模拟的长度和时间尺度，并开辟了研究氧化石墨烯膜和分散体稳定性的可能性。使用新模型，将评估氧化石墨烯处理含有一些最有问题和最危险的放射性物质（如铀，钚，铯和锶）的废水的功效，提供下一阶段工艺开发所需的相关物理和热力学数据。氧化石墨烯的设计和性能将得到优化，以提高特定污水处理挑战的去污系数。因此，该项目有可能彻底改变放射性污水处理技术。

The safe decommissioning of facilities used in the nuclear fuel cycle (nuclear fuel reprocessing, research and development and energy production) is a major socio-economic challenge facing the UK, with a predicted total cost of £120bn over the next 120 years. The decommissioning process will generate large volumes of water-based waste (effluent) which is radioactive and must be treated. As well as a number of specific challenges associated with the current materials and processes used to treat effluent, many new challenges are likely arise in the near future as decommissioning activity gathers pace. Overcoming these challenges is critical in the context of establishing public confidence in the management of radioactive waste as well as underpinning the UK's long-term energy strategy. Graphene oxide, a derivative of graphene with a high oxygen content, has exceptional properties which have already been demonstrated in other fields (e.g. desalination), and may be able to overcome the limitations faced by the materials currently used in effluent treatment. Graphene oxide could be used to treat effluents in two separate ways. Firstly, graphene oxide flakes could be added to the effluent and used to directly bind radioactive species (adsorption). Alternatively, a semi-permeable membrane, fabricated from individual graphene oxide flakes, could be used to sieve out the radioactive species (filtration).In this innovative and ambitious project, the science underpinning the use of graphene oxide in nuclear effluent treatment will be developed using a methodology led by computer simulation. Firstly, the development of new 'coarse-grained' models of graphene oxide will significantly extend the length and time scales accessible to simulation and open up the possibility of investigating the stability of graphene oxide membranes and dispersions. Using the new models, the efficacy of graphene oxide for the treatment of effluents containing some of the most problematic and dangerous radioactive species (e.g. uranium, plutonium, caesium and strontium) will be assessed, delivering the relevant physical and thermodynamic data required for the next stage of process development. The design and performance of graphene oxide will be optimised to improve decontamination factors for specific effluent treatment challenges. As a result, the project has the potential to revolutionise the techniques used in the treatment of radioactive effluent.