Impact of the microstructural and micromechanical variability on the long term behavior prediction of Zr-2.5Nb pressure tubes used in CANDU reactors

微观结构和微观机械变化对 CANDU 反应堆中使用的 Zr-2.5Nb 压力管的长期行为预测的影响

• 批准号: 364827-2009
• 负责人: Gauvin, Raynald
• 金额: $ 4.9万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=460824
• 关键词: Impact; microstructural; micromechanical; variability; long

This project aims to understand the variability of the creep behavior of the pressure tubes in CANDU reactors and its relations to microstructural differences found within these pressure tubes. This variability results in an uncertainty in the lifetime prediction for these materials (typically Zr-Nb alloys), a major problem for this industry. We propose a combined experimental approach including extensive characterization of the microstructure and bulk creep testing on representative microstructures. This will provide direct correlation between creep behavior and the microstructure of a pressure tube. Advanced microscopy techniques will identify and characterize representative microstructures and dislocation sub-structures found in CANDU reactor tubes with micro structural parameters obtained with statistical methods. These advanced electron microscopy techniques are electron backscattering diffraction patterns (EBSD) obtained in a field emission scanning electron microscope (FE-SEM), three dimensional microstructure with combined focus ion beam (FIB) and FE-SEM microscopes using EBSD and x-ray microanalysis and start of the art field emission scanning transmission electron microscopy (FE-STEM) with a Cs aberration corrector having sub - Angstrom resolution equipped with an EDS x-ray detector. Nanoindentation will also be used to evaluate the mechanical properties of these microstructures and also of their individual phases. The parameters describing the microstructure of these alloys will be used to create model, based on Levitin's theory [1], to predict the lifetime of Zr-Nb alloys for CANDU pressure tubes. An accurate prediction of the lifetime of pressure tubes for CANDU reactors will allow for more efficient use of nuclear energy at a time when green house gas are an issue and a reduced dependence on conventional fuels, such as oil and coal, is needed. Since Gentilly II will be refurnished in 2011, this project needs to generate predictive data by the end of 2010.

本项目旨在了解CANDU反应堆中压力管蠕变行为的可变性及其与这些压力管中发现的微观结构差异的关系。这种可变性导致这些材料（通常是Zr-Nb合金）寿命预测的不确定性，这是该行业的一个主要问题。我们提出了一种结合的实验方法，包括广泛的微观结构表征和代表性微观结构的体蠕变测试。这将提供蠕变行为与压力管微观结构之间的直接关联。先进的显微技术将识别和表征CANDU反应器管中具有代表性的微观结构和位错子结构，并通过统计方法获得微观结构参数。这些先进的电子显微镜技术是在场发射扫描电子显微镜（FE-SEM）中获得的电子后向散射衍射图（EBSD），使用EBSD和x射线显微分析的联合聚焦离子束（FIB）和FE-SEM显微镜的三维微观结构，以及具有亚埃分辨率的Cs像差校正器的场发射扫描透射电子显微镜（FE-STEM），配备了EDS x射线探测器。纳米压痕也将用于评估这些微观结构及其各个相的机械性能。描述这些合金微观结构的参数将用于建立基于Levitin的[1]理论的模型，以预测用于CANDU压力管的Zr-Nb合金的寿命。对CANDU反应堆压力管寿命的准确预测，将有助于在温室气体成为问题、需要减少对石油和煤炭等传统燃料的依赖之际，更有效地利用核能。由于Gentilly II将于2011年重新装修，因此该项目需要在2010年底之前生成预测数据。