The micromechanics of fracture of hydrides in Zr-2.5Nb CANDU pressure tubes

Zr-2.5Nb CANDU压力管中氢化物断裂的微观力学

• 批准号: 560391-2020
• 负责人: Abdolvand, Hamidreza
• 金额: $ 3.01万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=721769
• 关键词: micromechanics; fracture; hydrides; Zr; 2.5Nb; micromechanics; fracture; hydrides; Zr; 2.5Nb

CANDU reactors have been contributing significantly in providing clean energy to Ontario and Canada. More than 50% of electricity in Ontario is generated by CANDU reactors. Most of CANDU reactors are built in 1970s and 1980s and are aging. In order to continue to operate these reactors, engineers are required to demonstrate to regulatory authorities that they are safe. One of the main components that determine the lifetime of CANDU reactors is the zirconium-alloy pressure tubes that contain fuel bundles and separate the hot water coolant from the cold moderator. During operation, hydrogen from hot water diffuses towards the flaws induced in the tube and with time, forms a brittle phase called zirconium hydrides. To ensure the integrity of the tubes and safety of the reactors, it is important to show that a crack will not nucleate in these hydrides. This project focuses on using advanced numerical techniques and diffraction-based experiments to understand how the hydrides that form in the vicinity of flaws will crack and how such cracks lead to failure. Finite element models will be developed and used at Western University, and with the help of graduate students, experiments will be done at Canadian Nuclear Laboratories to study formation of cracks at nano and meso-scales. This will help understand the underlying mechanisms that control fracture of hydrides.The results from this research are expected to help improve the accuracy of the models used in nuclear industry and improve the lifetime of the pressure tubes used in the core of CANDU reactors.

Candu反应堆在为安大略省和加拿大提供清洁能源方面做出了重大贡献。安大略省的电力超过50％是由Candu反应堆产生的。大多数Candu反应堆建于1970年代和1980年代，并且正在老化。为了继续操作这些反应堆，需要工程师向监管机构证明他们是安全的。确定CANDU反应器寿命的主要组件之一是含有燃料束并将热水冷却液与冷主持人分开的锆合金压力管。在操作过程中，来自热水的氢向管中引起的缺陷扩散，随着时间的流逝，形成了一个脆性相，称为锆氢化物。为了确保管子的完整性和反应堆的安全性，重要的是要证明裂纹不会在这些氢化物中成核。该项目的重点是使用先进的数值技术和基于衍射的实验，以了解缺陷附近形成的氢化物将如何破裂以及这种裂缝如何导致故障。有限元模型将在西部大学开发和使用，并在研究生的帮助下，将在加拿大核实验室进行实验，以研究Nano和Meso-Scales的裂缝形成。这将有助于理解控制氢化物断裂的潜在机制。这项研究的结果有望帮助提高核工业中使用的模型的准确性，并改善Candu反应器核心中使用的压力管的寿命。