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枯竭和减少温室气体排放，是21世纪规模最大的挑战之一。目前，世界上约15%的电力来自核裂变能源，这是所有非温室气体排放资源中最大的供应量，如果英国要在2050年实现净零碳排放的目标，这将是至关重要的，英国在欣克利角C建造的20年来第一座核电站就证明了这一点。然而，正在开发新材料来提高现有核反应堆的固有安全性，并用于未来的核电站技术。本项目将研究的燃料材料包括硅化铀、氮化物和硼化物以及包层材料碳化硅、碳化锆和氮化锆，以评估它们用于当前和下一代核电站的可行性，利用离子束辐照来模拟核反应堆的条件，并对辐照后的材料进行深入的表征。这些新型燃料材料是取代目前铀氧化物燃料组件的有力候选者，因为它们的导热系数要高得多，这将降低燃料温度，并在类似福岛事故的事故中赢得至关重要的时间。覆层材料的熔化温度也比目前水冷反应堆中使用的锆合金高得多，因此将推迟甚至缓解熔毁情况。如果这些材料能够在目前的核反应堆中证明自己是出于这些原因，它们也将有望部署在下一代核电站中，这些核电站将在更高的温度和更极端的辐射损害下运行。中子轰击造成的辐射损伤会导致原子位移，从而导致材料中的缺陷随着温度的变化而演变。除了这种缺陷的积累，气体(如氢和氦)可以从变形反应中积累。这些气体与形成的缺陷相互作用，会进一步降低机械和热物理性能。辐射损伤对这些先进的非氧化物陶瓷性能的影响的研究还处于初级阶段，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。该项目将使用核燃料卓越中心和道尔顿坎布里亚设施(DCF)的设施，与亨利·罗伊斯研究所合作，在辐照后制造、辐射和执行材料的微结构和纳米结构表征。然后，牛津大学和麻省理工学院的项目合作伙伴将对这些材料进行热分析，以回答关键问题--辐射损害对这些材料优越的导热系数有什么影响，它们是否会降到开发这些新材料变得不经济的水平？最后，通过对辐射损伤对其微纳结构影响的高度详细的了解，我们是否可以对这些材料进行反向工程

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