Approximately 130,000 metal fuel pins were irradiated in the Experimental Breeder Reactor II (EBR-II) during its 30 years of operation to develop and characterize existing and prospective fuels. For many of the metal fuel irradiation experiments, neutron radiography imaging was performed to characterize fuel behavior, like fuel swelling. However, due to the lack of technology or resources, many of the images have not been processed or were processed manually through visual examination. This paper represents first-attempt to develop an image processing algorithm capable of automatically extracting information regarding the degree of fuel swelling from neutron radiography imaging. The algorithm was applied to 120 images of three different metallic fuel pin compositions—U-10Zr, U-8Pu-10Zr, and U-19Pu-10Zr. The algorithm performs operations of image intensity adjustment, image binarization, region finding, and labeling to extract information about fuel swelling. The average growth for U-10Zr was found to be 8.49% with 95% Confidence Interval (CI) [8.33 –8.66%], for U-8Pu-10Zr — 7.50% with 95% CI [7.23 – 7.78%], and for U-19Pu-10Zr — 3.15%, with 95% CI [2.40 – 3.91%]. The results obtained by applying this automatic image processing algorithm are consistent with previously reported studies of the same types of fuels. The automatic image processing algorithm will be expanded to include thousands of available neutron radiography images and different types of fuels to investigate empirical dependencies of fuel swelling, which can be subsequently applied to advanced fuel modeling. Results from this study can later be compared to BISON simulations to further benchmark modeling efforts and develop assessment cases.

实验增殖反应堆 II (EBR-II) 在运行 30 年期间，大约有 130,000 个金属燃料细棒受到辐照，以开发和表征现有和未来的燃料。对于许多金属燃料辐照实验，进行了中子射线照相成像以表征燃料行为，如燃料膨胀。然而，由于缺乏技术或资源，许多图像没有经过处理或通过目视进行人工处理。本文首次尝试开发一种图像处理算法，该算法能够从中子射线照相成像中自动提取有关燃料膨胀程度的信息。该算法应用于三种不同金属燃料棒成分的 120 张图像——U-10Zr、U-8Pu-10Zr 和 U-19Pu-10Zr。该算法执行图像强度调整、图像二值化、区域查找和标记操作以提取有关燃料膨胀的信息。发现 U-10Zr 的平均增长率为 8.49%，置信区间 (CI) 为 95% [8.33 –8.66%]，U-8Pu-10Zr 的平均增长率为 7.50%，置信区间为 95% [7.23 – 7.78%]，对于U-19Pu-10Zr — 3.15%，95% CI [2.40 – 3.91%]。通过应用这种自动图像处理算法获得的结果与先前报道的相同类型燃料的研究结果一致。自动图像处理算法将扩展到包括数千个可用的中子射线照相图像和不同类型的燃料，以研究燃料膨胀的经验依赖性，随后可将其应用于高级燃料建模。