New Fuel Assemblies for Advanced Nuclear Technologies

满足日益增长的人口对能源的需求，同时解决化石燃料的消耗和减少温室气体是21世纪世纪最大规模的挑战之一。目前，世界上约有15%的电力是由核裂变能源产生的，这是任何非温室气体排放资源的最大供应，如果英国要实现其到2050年净零碳排放的目标，这将对该国的能源结构至关重要。然而，正在开发新材料，以提高目前核反应堆的固有安全性，并用于未来的核电站技术。本项目研究的燃料材料包括硅化铀、氮化铀和硼化铀，包壳材料、碳化硅、碳化锆和氮化锆将通过使用离子束辐照模拟核反应堆的条件进行研究，以评估其在当前和下一代核电站中使用的可行性，并对辐照后的材料进行深入表征。这些新型燃料材料是替代当前铀氧化物燃料组件的强有力的候选者，这是由于它们的高得多的导热性，这将降低燃料温度并在事故场景（诸如福岛事故）中赢得关键时间。包壳材料也具有比目前在水冷反应堆中使用的Zr合金高得多的熔化温度，因此将延迟或甚至减轻熔毁情况。如果这些材料能够在目前的核反应堆中得到应用，它们也将有望应用于下一代核电站，这些核电站将在更高的温度和更极端的辐射损伤下运行。中子轰击的辐射损伤会导致原子位移，从而导致材料中的缺陷，这些缺陷会随着温度的变化而变化。除了这种缺陷的积累，气体（如氢和氦）可以从嬗变反应中积累。这些气体与形成的缺陷相互作用，并可进一步降低机械和热物理性能。辐射损伤对这些先进非氧化物陶瓷性能影响的研究还处于起步阶段，在进一步开发和最终部署这些材料之前，需要更好地了解这些材料。该项目将利用核燃料卓越中心和亨利罗伊斯研究所内的道尔顿坎布里亚设施（DCF）的设施来制造，辐照并在辐照后对材料进行微米和纳米结构表征。材料的热分析将在牛津大学和马萨诸塞州理工学院（MIT）的项目合作伙伴处进行，并将回答关键问题-辐射损伤对这些材料的上级导热性有什么影响，以及它们是否会下降到开发这些新材料变得不经济的水平？最后，从辐射损伤对其微纳结构影响的高度详细了解，我们能否对这些材料进行逆向工程

Meeting the growing energy demand from an increasing population, whilst addressing the depletion of fossil fuels and reducing greenhouse gases is the one of the grandest scale challenges of the 21st century. Currently, around 15% of the world's electricity is generated by nuclear fission energy, the largest supply by any non-greenhouse gas emitting resource and it will be critical to the country's energy mix if the UK is to meet its goal of net zero carbon emissions by 2050 as evidenced by the construction the UKs first nuclear power plant in two decades at Hinkley point C. However, new materials are being developed to improve the intrinsic safety of current nuclear reactors and for deployment in future nuclear power plant technologies. The fuel materials to be studied in this project include uranium silicide, nitride and boride and cladding materials, silicon carbide, zirconium carbide and zirconium nitride will be studied to asses their feasibility for use in current and next generation nuclear power plants by using ion beam irradiation to mimic the conditions of a nuclear reactor and performed an in-depth characterisation of the materials post irradiation. These novel fuel materials are strong candidates to replace current uranium oxide fuel assemblies due to their much higher thermal conductivity, which will reduce fuel temperatures and buy vital time in an accident scenario, such as Fukushima like accident. The cladding materials also have much higher melting temperature than the currently used Zr alloy in water cooled reactors and so would delay or even mitigate meltdown scenarios. If these materials can prove themselves in current nuclear reactors for these reasons, they will also be promising for deployment in next generation nuclear power plants which will operate at much higher temperatures and under more extreme radiation damage.Radiation damage from neutron bombardment causes atomic displacement which leads to defects in materials that can evolve as a function of temperature. In addition to this build-up of defects, gases (such as hydrogen and helium) can accumulate from transmutation reactions. These gases interact with the defects formed and can further degrade the mechanical and thermophysical properties. Research into the effects of radiation damage on the properties of these advanced non-oxide ceramics are in their infancy and will need to be better understood before the materials can be developed further and eventually deployed.This project will use facilities at the Nuclear Fuel Centre for Excellence and the Dalton Cumbria Facility (DCF) based withing the Henry Royce Institute to manufacture, irradiate and perform micro and nano-structural characterisation of the materials post irradiation. Thermal analysis of the materials will then be performed at project partners at the University of Oxford and The Massachusetts Institute of Technology (MIT) will answer the key question - what effect does radiation damage have on the superior thermal conductivity of these materials and do they fall to levels below which developing these new materials becomes uneconomical? Finally, from the highly detailed understanding of the effect of radiation damage on their micro and nano-structure, can we reverse engineer these materials