Abstract In a loss of coolant accident (LOCA), fuel cladding deformation is an important factor in terms of maintaining coolable geometry. In order to simulate the cladding deformation behavior, experimental research and the development of a fuel performance code have been conducted. In addition, relevant experimental data concerning the major phenomena for validating the developed code are required. Therefore, in this study, an experimental apparatus named ‘DIMAT’ (Deformation In-situ Measurement Apparatus by image-analysis Technique) is developed to produce high temperature cladding tube deformation data. In order to simulate various accident conditions, an infrared (IR) furnace and pressure injection equipment were assembled. Additionally, the cladding specimen in the IR furnace was clearly recorded by application of high temperature resistant black spray paint and modification of a quartz tube. Some uncertainty factors that might arise due to the paint application were considered and evaluated. After the deformation behavior in a scenario was recorded, the in-situ hoop strain of the cladding was calculated through the developed image analysis method. To ensure accuracy of the established image analysis system, a validation experiment and uncertainty evaluation were performed. Finally, the burst experiments were carried out at low and high heating rates of 1, 14, and 28 °C/s, and consequently the in-situ high temperature strain rate was successfully measured in each experimental case.

中文翻译：

---

使用光学图像分析在各种瞬态加热条件下对 Zircaloy-4 熔覆管进行原位变形测量

摘要 在失冷事故（LOCA）中，燃料包壳变形是保持可冷却几何形状的重要因素。为了模拟包壳变形行为，已经进行了实验研究和燃料性能代码的开发。此外，还需要有关验证开发代码的主要现象的相关实验数据。因此，在本研究中，开发了一种名为“DIMAT”（通过图像分析技术的变形现场测量装置）的实验装置来产生高温熔覆管变形数据。为了模拟各种事故条件，组装了红外（IR）炉和压力注入设备。此外，通过应用耐高温黑色喷漆和修改石英管，IR 炉中的熔覆样品被清楚地记录下来。考虑和评估了可能因涂料应用而产生的一些不确定因素。在记录了场景中的变形行为后，通过开发的图像分析方法计算了包层的原位环向应变。为确保建立的图像分析系统的准确性，进行了验证实验和不确定性评估。最后，在1、14和28°C / s的低加热速率和高加热速率下进行爆裂实验，因此在每个实验案例中都成功地测量了原位高温应变速率。考虑和评估了可能因涂料应用而产生的一些不确定因素。在记录了场景中的变形行为后，通过开发的图像分析方法计算了包层的原位环向应变。为确保建立的图像分析系统的准确性，进行了验证实验和不确定性评估。最后，在1、14和28°C / s的低加热速率和高加热速率下进行爆裂实验，因此在每个实验案例中都成功地测量了原位高温应变速率。考虑和评估了可能因涂料应用而产生的一些不确定因素。在记录了场景中的变形行为后，通过开发的图像分析方法计算了包层的原位环向应变。为确保建立的图像分析系统的准确性，进行了验证实验和不确定性评估。最后，在1、14和28°C / s的低加热速率和高加热速率下进行爆裂实验，因此在每个实验案例中都成功地测量了原位高温应变速率。为确保建立的图像分析系统的准确性，进行了验证实验和不确定性评估。最后，在1、14和28°C / s的低加热速率和高加热速率下进行爆裂实验，因此在每个实验案例中都成功地测量了原位高温应变速率。为确保建立的图像分析系统的准确性，进行了验证实验和不确定性评估。最后，在1、14和28°C / s的低加热速率和高加热速率下进行爆裂实验，因此在每个实验案例中都成功地测量了原位高温应变速率。