The effect of vanadium and copper on defect structure generation during neutron irradiation of zirconium-based materials

钒和铜对锆基材料中子辐照过程中缺陷结构生成的影响

• 批准号: 2574336
• 金额: --
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2574336
• 关键词: effect; vanadium; copper; defect; structure

In modern nuclear reactors, zirconium alloys are used for encapsulating nuclear fuel. Zirconium alloys are used because they are very transparent to neutrons, have excellent corrosion properties in a water-cooled reactor and have reasonable mechanical strength. Zirconium alloys are constantly developed further in order to utilise nuclear fuel assemblies in a reactor for longer than what is achieved today. In fact, it is the performance of the encapsulating zirconium alloys that determines how much energy can be extracted from nuclear fuel and not the enrichment level. An improvement of the so-called 'burn-up' will result in fewer reactor shut-downs and more power generation per unit of nuclear waste.Nuclear reactor cores are one of the most demanding environment for structural materials. When inserted into a reactor, zirconium alloys undergo corrosion, hydrogen pick up and significant levels of irradiation damage as they encapsulate nuclear fuel. Irradiating a metal like zirconium results in very dramatic microstructural changes and therefore alterations of the performance. Hence, very detailed understanding of the microstructural evolution during irradiation is highly desirable. The irradiation-induced damage evolution also has very important consequences for the material properties such as irradiation hardening and irradiation-induced dimensional changes. The latter is of particular interest for this project as the dimensional changes are greatly affected by alloy chemistries. To date, a clear understanding of the relationship between alloy chemistry, development of defect structure during irradiation and irradiation-induced dimensional instabilities is still missing, which is a particular issue when trying to develop new Zr-alloys. Aims:The PhD project will focus on two development alloys, one with V and one with Cu additions, which were irradiated in the BOR-60 research reactor. - X-ray diffraction-based line profile analysis will be utilised to obtain dislocation line densities for both alloys irradiated to five different fluence levels. - In addition, detailed electron microscopy analysis will explore loop arrangements and the role of Cu and V using high resolution EDX mapping. The findings will be compared with ongoing analyses of more conventional Zr-alloys irradiated during the same irradiation campaign.- Inform modelling of irradiation damage evolution. The student's work will feed into 'MIDAS', a £9M EPSRC programme grant (EP/S01702X/1) led by Manchester, with partners at Oxford, Imperial and Culham Centre for Fusion Energy, alongside a range of UK and international research and industrial stakeholders. Academic Novelty:New insight into the impact of novel alloy additions to irradiation induced defects that form and their evolution. To date no detailed study of these materials have been performed following neutron irradiation. The work will build on the ongoing working applying new characterization techniques to existing commercial alloy.

在现代核反应堆中，锆合金用于封装核燃料。使用锆合金是因为它们对中子非常透明，在水冷反应堆中具有出色的腐蚀特性，并且具有合理的机械强度。为了在反应堆中使用核燃料组件的时间比当今所获得的时间更长，因此不断开发锆合金。实际上，封装的锆合金的性能决定了从核燃料而不是富集水平中提取多少能量。所谓的“燃烧”的改善将导致较少的反应堆关闭和每单位核废料发电更多。核反应堆核心是结构材料最苛刻的环境之一。当插入反应堆中时，锆合金在封装核燃料时会经历腐蚀，氢气拾取和显着水平的辐射损伤。照射像锆等金属会导致非常巨大的微结构变化，从而改变了性能。因此，非常需要对辐射过程中的微观结构进化的非常详细的理解。辐照引起的损伤演化对诸如辐照硬化和辐照诱导的尺寸变化等物质特性也具有非常重要的后果。后者对该项目特别感兴趣，因为尺寸变化受合金化学的影响很大。迄今为止，仍然缺少对合金化学，辐射过程中缺陷结构的发展，缺陷结构之间的关系的明确理解，而在试图开发新的ZR合金时，这是一个特殊的问题。目的：博士项目将集中在两种开发合金上，一种具有V，一种带有CU添加的合金，这些合金在BOR-60研究反应堆中被辐照。 - 将利用基于X射线衍射的线曲线分析来获得两种合金的脱位线密度，均被照射为五个不同的通量水平。 - 此外，详细的电子显微镜分析将使用高分辨率EDX映射探索循环排列和CU和V的作用。这些发现将与对在同一辐照运动中受辐照的更常规ZR合金的持续分析进行比较。该学生的工作将以曼彻斯特领导的900万英镑的EPSRC计划赠款（EP/S01702X/1）为“ MIDAS”，与牛津，帝国和库勒姆融合能源中心的合作伙伴以及英国以及国际研究和工业利益相关者以及一系列的合作伙伴。学术新颖性：对新型合金对辐照的影响的新见解，诱发的缺陷及其进化。迄今为止，在中子照射后尚未对这些材料进行详细研究。这项工作将基于正在进行的工作，将新的特征技术应用于现有的商业合金。