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优异的腐蚀性能，并且具有合理的机械强度。锆合金不断得到进一步发展，以便在反应堆中使用核燃料组件的时间比今天更长。事实上，正是封装锆合金的性能决定了可以从核燃料中提取多少能量，而不是浓缩水平。所谓“燃耗”的改善将减少反应堆的关闭次数，提高每单位核废料的发电量。核反应堆堆芯是对结构材料要求最高的环境之一。当插入反应堆时，锆合金在封装核燃料时会遭受腐蚀、氢吸收和严重的辐射损伤。辐照金属如锆会导致非常显著的微观结构变化，从而改变性能。因此，非常详细的了解辐照过程中的微观结构演变是非常可取的。辐照损伤演化对材料的辐照硬化和辐照尺寸变化等性能也有重要影响。后者对该项目特别感兴趣，因为尺寸变化受合金化学成分的影响很大。迄今为止，合金化学之间的关系，辐照过程中的缺陷结构的发展和辐照引起的尺寸不稳定性的一个清晰的理解仍然是失踪，这是一个特殊的问题时，试图开发新的锆合金。目标：博士项目将侧重于两种开发合金，一种添加V，一种添加Cu，在BOR-60研究反应堆中进行辐照。- 基于X射线衍射的线轮廓分析将被用来获得两种合金的位错线密度照射到五个不同的能量密度水平。- 此外，详细的电子显微镜分析将探索环的安排和铜和V的作用，使用高分辨率EDX映射。研究结果将与在同一辐照活动期间辐照的更传统的锆合金的持续分析进行比较。告知辐照损伤演变的建模。该学生的工作将纳入'MIDAS'，这是一项由曼彻斯特领导的900万英镑EPSRC计划拨款（EP/S 01702 X/1），与牛津，帝国和卡勒姆聚变能源中心的合作伙伴，以及一系列英国和国际研究和工业利益相关者。学术新奇：对新型合金添加剂对辐照诱导缺陷形成及其演变的影响的新见解。到目前为止，还没有对这些材料进行中子辐照后的详细研究。这项工作将建立在正在进行的工作应用新的表征技术，以现有的商业合金。