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，锆合金被用于封装核燃料，因为锆合金对中子非常透明，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，因此锆合金不断得到进一步发展。事实上，是封装锆合金的性能决定了核燃料组件在反应堆中的使用时间。能量可以从核燃料中提取，而不是从浓缩水平中提取。所谓“燃耗”的改善将导致反应堆关闭次数减少，单位核废料的发电量增加。核反应堆堆芯是其中之一。当锆合金被插入反应堆时，会遭受腐蚀、氢吸收和严重的辐射损伤，因为它们封装了核燃料，会导致非常严重的后果。因此，非常需要非常详细地了解辐照期间的微观结构演变，辐照引起的损伤演变对于材料性能（例如辐照硬化和辐照引起的尺寸变化）也具有非常重要的影响。后者对该项目特别感兴趣，因为尺寸变化很大程度上受到合金化学成分的影响。迄今为止，人们已经清楚地了解了合金化学成分、辐照过程中缺陷结构的发展和缺陷结构之间的关系。辐照引起的尺寸不稳定性仍然存在，这是尝试开发新型锆合金时的一个特殊问题。 目标：博士项目将重点关注两种开发合金，一种添加了 V，另一种添加了 Cu，这些合金在 BOR 中进行了辐照。 -60 研究堆。 - 基于 X 射线衍射的线轮廓分析将用于获得两种合金在五个不同注量水平下的位错线密度。此外，详细的电子显微镜分析将使用高分辨率 EDX 绘图探索环排列以及 Cu 和 V 的作用，这些结果将与在同一辐照活动期间辐照的更传统 Zr 合金的持续分析进行比较。- 为辐照损伤建模提供信息。该学生的工作将被纳入“MIDAS”，这是一项由曼彻斯特大学牵头、与牛津大学、帝国理工学院和牛津大学合作的 900 万英镑 EPSRC 项目拨款 (EP/S01702X/1)。卡勒姆聚变能源中心以及一系列英国和国际研究和工业利益相关者：关于新型合金添加物对辐照引起的缺陷形成及其演变的影响的新见解迄今为止，尚未对这些材料进行详细研究。这项工作将建立在将新的表征技术应用于现有商业合金的基础上。