Post-ballooning and burst steam oxidation of accident tolerant zirconium alloy cladding with cracked chromium coating

IF 3.2 2区工程技术 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Nuclear Materials Pub Date : 2025-08-06 DOI:10.1016/j.jnucmat.2025.156095

Hyunwoo Yook, Sunghoon Joung, Youho Lee

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引用次数: 0

Abstract

This study presents a mechanistic model for coating cracking and subsequent oxidation of burst Cr-coated Zircaloy cladding under Design Basis Accident (DBA) conditions. A series of sequential simulated Loss Of Coolant Accident (LOCA) experiments were conducted using the i-LOCA facility and the high-temperature oxidation facility at Seoul National University. 1.5 m long Cr-coated claddings(15μm) with inserted ZrO₂ pellets were internally pressurized and inductively heated in an inert environment using the i-LOCA facility to induce ballooning and burst under various internal pressures and two pellet configurations—cylindrical and single powder pellet—designed to simulate unfragmented (<55 GWd/MTU) and fully pulverized (∼94 GWd/MTU) fuel conditions, respectively. The resulting post-burst cladding geometries with various burst hoop strains were analyzed via 3D scanning. The burst region (±1.5 inches from the burst center) of the post-burst specimens was subsequently subjected to two-sided oxidation using the high-temperature oxidation facility.

Mechanistic models for coating cracking and Equivalent Cladding Reacted (ECR) calculation were developed based on the conventional definition of ECR and a phenomenological understanding derived from microstructural characterization of post-burst specimens, thereby providing a general framework applicable irrespective of the specific coating. Under DBA conditions, the additional oxidation attributable to coating cracking was quantified to be no more than 25 % relative to inner-sided oxidation. Accident coping time analyses indicated that, even when accounting for burst-induced deformation and coating cracking, the application of Cr coating maintains compliance with existing regulatory safety margins.

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裂纹铬包覆锆合金后气胀及爆裂蒸汽氧化的研究

本研究提出了在设计基础事故（DBA）条件下，爆炸cr包覆锆合金包层开裂和随后氧化的机理模型。利用i-LOCA设备和首尔大学的高温氧化设备进行了一系列连续模拟冷却剂损失事故（LOCA）实验。在惰性环境中，使用i-LOCA设备对插入ZrO2球团的1.5 m长cr包层（15μm）进行内部加压和感应加热，在不同的内压和两种球团结构（圆柱形和单粉球团）下诱导气球膨胀和破裂分别模拟未破碎（55 GWd/MTU）和完全粉碎（~ 94 GWd/MTU）的燃料条件。通过三维扫描分析了不同爆炸环箍应变下的爆炸后包层几何形状。爆炸后试样的爆炸区域（距离爆炸中心±1.5英寸）随后使用高温氧化设备进行双面氧化。基于ECR的传统定义和爆后试样微观结构特征的现象学理解，开发了涂层开裂和等效包层反应（ECR）计算的机制模型，从而提供了一个适用于特定涂层的总体框架。在DBA条件下，可归因于涂层开裂的额外氧化被量化为相对于内部氧化不超过25%。事故应对时间分析表明，即使考虑到爆炸引起的变形和涂层开裂，Cr涂层的应用仍符合现有法规的安全边际。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Nuclear Materials 工程技术-材料科学：综合

CiteScore

5.70

自引率

25.80%

发文量

601

审稿时长

63 days

期刊介绍： The Journal of Nuclear Materials publishes high quality papers in materials research for nuclear applications, primarily fission reactors, fusion reactors, and similar environments including radiation areas of charged particle accelerators. Both original research and critical review papers covering experimental, theoretical, and computational aspects of either fundamental or applied nature are welcome. The breadth of the field is such that a wide range of processes and properties in the field of materials science and engineering is of interest to the readership, spanning atom-scale processes, microstructures, thermodynamics, mechanical properties, physical properties, and corrosion, for example. Topics covered by JNM Fission reactor materials, including fuels, cladding, core structures, pressure vessels, coolant interactions with materials, moderator and control components, fission product behavior. Materials aspects of the entire fuel cycle. Materials aspects of the actinides and their compounds. Performance of nuclear waste materials; materials aspects of the immobilization of wastes. Fusion reactor materials, including first walls, blankets, insulators and magnets. Neutron and charged particle radiation effects in materials, including defects, transmutations, microstructures, phase changes and macroscopic properties. Interaction of plasmas, ion beams, electron beams and electromagnetic radiation with materials relevant to nuclear systems.