Enhancing nuclear fuel efficiency through improved understanding of irradiation damage in zirconium cladding

通过加深对锆包壳辐照损伤的了解来提高核燃料效率

• 批准号: EP/I005420/1
• 负责人: Michael Preuss
• 金额: $ 191.13万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FI005420%2F1
• 关键词: Enhancing; nuclear; fuel; efficiency; through

This project focuses on energy and more specifically on nuclear fission. Core material such as fuel assemblies are exposed to irradiation from the moment a nuclear reactor is switched on. The bombardment of material with neutrons creates collision cascades that immediately produce point defects and dislocations in the material. This results in very significant changes of the material properties compared to non-irradiated material.Nuclear fuel for light water reactors is contained by so-called cladding tubes, which are made from zirconium alloys because of their excellent corrosion resistance, sufficient mechanical properties and their low neutron absorption coefficient. Nuclear fuel is enriched initially with 5% 235U. However, the fuel cannot be fully burned due to the uncertainty of clad material degradation and dimensional instability of fuel assemblies. The dimensional instabilities are related to irradiation growth and creep of zirconium alloys. Irradiation growth occurs in zirconium alloys without applying any external load and is due to the hexagonal close packed crystal structure of zirconium. Irradiation creep is significantly faster than thermal creep due to the increased density of vacancies in irradiated material. The safe operation of nuclear fuel assemblies requires dimensional stability to ensure sufficient coolant flow and the safe operation of control rods when needed. Irradiation growth and creep can lead to bowing and buckling of fuel assemblies, which is of concern with current plants and even more a concern for increased burnup of the nuclear fuel. Consequently, we need to develop a detailed understanding of the mechanisms leading to these phenomena and how they are affected by material chemistry and the microstructure evolution during irradiation.Traditionally, microstructure and damage characterisation of irradiated material is mainly carried out by electron microscopy. However, in the last decade, very powerful 3rd generation synchrotron radiation sources have been built, which represent a tremendous opportunity to develop complementary tools or quantitative characterisation of irradiation damage and microstructure evolution.During the 1960s and 70s many countries including the UK had test reactors that allowed scientists to undertake research on irradiated material. However, most of these test reactors are gone now and it is unlikely that the UK or other countries will build many new test reactors. For this reason, governments have invested in proton/ion accelerators to simulate neutron irradiation. The advantage of such facilities is that they are by many order of magnitudes cheaper to run than a test reactor. However, our understanding of how well neutron induced damage is related to proton/ion induced damage is limited. Since Zr alloys are relatively mildly active when irradiated by neutrons, they represent also an ideal material to calibrate proton/ion against neutron irradiation.During the fellowship my research group will:- identify the role of alloy chemistry and microstructure on irradiation growth and creep of fuel clad,- for the first time extensively use synchrotron radiation to characterise irradiation damage and- calibrate proton/ion irradiated against neutron irradiated cladding material in order to use the convenience of the former (non-active material, easily irradiated to different levels in a short time) to identify the route cause for loop formation resulting in breakaway growth

该项目的重点是能源，更具体地说是核裂变。从核反应堆启动的那一刻起，燃料组件等核心材料就会受到辐射。中子轰击材料会产生碰撞级联，立即在材料中产生点缺陷和位错。与未辐照材料相比，这导致材料性能发生非常显着的变化。轻水反应堆的核燃料包含在所谓的包壳管中，包壳管由锆合金制成，因为它们具有优异的耐腐蚀性、足够的机械性能和中子吸收系数低。核燃料最初浓缩为 5% 235U。然而，由于包层材料降解的不确定性和燃料组件的尺寸不稳定性，燃料无法完全燃烧。尺寸不稳定性与锆合金的辐照生长和蠕变有关。锆合金在不施加任何外部载荷的情况下会发生辐照生长，这是由于锆的六方密排晶体结构所致。由于辐照材料中的空位密度增加，辐照蠕变明显快于热蠕变。核燃料组件的安全运行需要尺寸稳定性，以确保足够的冷却剂流量和控制棒在需要时的安全运行。辐照增长和蠕变会导致燃料组件弯曲和扭曲，这是当前核电站所关心的问题，更会引起核燃料燃耗增加的问题。因此，我们需要详细了解导致这些现象的机制，以及它们如何受到材料化学和辐照过程中微观结构演变的影响。传统上，辐照材料的微观结构和损伤表征主要通过电子显微镜进行。然而，在过去十年中，非常强大的第三代同步加速器辐射源已经建成，这为开发补充工具或定量表征辐照损伤和微结构演化提供了巨大的机会。在 20 世纪 60 年代和 70 年代，包括英国在内的许多国家都拥有试验反应堆这使得科学家能够对辐照材料进行研究。然而，这些试验堆大部分已经消失，英国或其他国家不太可能建造许多新的试验堆。因此，各国政府投资了质子/离子加速器来模拟中子辐照。此类设施的优点是其运行成本比试验反应堆便宜许多数量级。然而，我们对中子引起的损伤与质子/离子引起的损伤之间的关系的理解是有限的。由于 Zr 合金在受到中子辐照时具有相对温和的活性，因此它们也是校准质子/离子对抗中子辐照的理想材料。在研究期间，我的研究小组将：- 确定合金化学和微观结构对辐照生长和蠕变的作用燃料包壳，-首次广泛使用同步加速器辐射来表征辐照损伤，并校准中子辐照包壳材料辐照的质子/离子，以便使用前者（非活性材料，很容易在短时间内照射到不同水平）方便识别环路形成导致分离生长的途径

项目成果

Ultrahigh Resolution EDX Spectrum Imaging: Nuclear Materials Applications

超高分辨率 EDX 光谱成像：核材料应用

• DOI: 10.1017/s143192761300768x
• 发表时间: 2013
• 期刊: Microscopy and Microanalysis
• 影响因子: 2.8
• 作者: Francis E

Iron redistribution in a zirconium alloy after neutron and proton irradiation studied by energy-dispersive X-ray spectroscopy (EDX) using an aberration-corrected (scanning) transmission electron microscope

使用像差校正（扫描）透射电子显微镜通过能量色散 X 射线光谱 (EDX) 研究中子和质子辐照后锆合金中铁的重新分布

• DOI: 10.1016/j.jnucmat.2014.08.034
• 发表时间: 2014
• 期刊: Journal of Nuclear Materials
• 影响因子: 3.1
• 作者: Francis E

The effect of aluminium on twinning in binary alpha-titanium

• DOI: 10.1016/j.actamat.2015.09.048
• 发表时间: 2016-01-15
• 期刊: ACTA MATERIALIA
• 影响因子: 9.4
• 作者: Fitzner, Arnas;Prakash, D. G. Leo;Preuss, Michael
• 通讯作者: Preuss, Michael

The Microstructure and strength of a V-5Cr-5Ti alloy processed by high pressure torsion

• DOI: 10.1016/j.msea.2019.04.094
• 发表时间: 2019-06-05
• 期刊: MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
• 影响因子: 6.4
• 作者: Fan, Zhijian;Joni, Bertalan;Ungar, Tamds
• 通讯作者: Ungar, Tamds

Modelling the interaction of primary irradiation damage and precipitates: Implications for experimental irradiation of zirconium alloys

模拟初级辐照损伤和析出物的相互作用：对锆合金实验辐照的影响

• DOI: 10.1016/j.jnucmat.2017.10.022
• 发表时间: 2018
• 期刊: Journal of Nuclear Materials
• 影响因子: 3.1
• 作者: Adrych-Brunning A