基于PGAI技术的板状核燃料可燃毒物元素分布检测方法研究

板状核燃料在小型核设备中具有重要的应用前景，其内部添加的可燃毒物均匀分布是保证燃料在反应堆内安全运行的前提。目前常规方法难以分析可燃毒物的元素分布，因此相关新型无损检测方法备受关注。瞬发伽马射线活化成像（PGAI）技术由于能对大体积样品内部的元素成分及位置进行分析，近年来成为核分析领域的研究热点。本项目基于PGAI技术对板状燃料中的可燃毒物进行元素分布检测研究。针对测量过程中样品体效应造成的元素定量分析不准确，拟从中子与样品反应的物理过程出发，揭示体效应影响测量结果准确性的机理并建立修正方法。对测量时间长且空间分辨率低等问题，拟通过编码孔成像技术提升测量信号的统计性，降低测量时间，在此基础上利用超分辨图像重构算法，提升测量结果的空间分辨率。该项目的研究及成果，将为PGAI技术在板状核燃料可燃毒物元素分布检测提供物理机制以及分析方法等理论支撑，对该技术的推广应用具有重要的科学价值。

Plate-type nuclear fuel has potential application in small nuclear devices. The uniform distribution of added burnable poisons is important for safe operation of nuclear fuel in reactor. The common methods can not be used to determine the elemental distribution of burnable poisons. Thus, the relative non-destructive technology is highly desirable. Prompt gamma activation imaging (PGAI) can be used for analyzing the elemental compositions and their corresponding positions of bulk sample, which is a research hotpot in the field of nuclear analysis in recent years. In this project, the elemental distributions of burnable poisons inside plate-typed nuclear fuel will be conducted based on PGAI technology. For solving the inaccuracy analysis of element quantitative caused by sample matrix effect, the main physical mechanism and correction method will be studied based on the reactions between neutrons and nuclides. For solving problems about long measuring time and low spatial resolution, the coded-aperture imaging method will be studied to improve the statistics of measurement signal to reduce measuring time. On this basis, the super resolution reconstruction method will be studied to improve the spatial resolution of results. This project will supply theoretical basis for the elemental distributions of burnable poisons inside plate-type nuclear fuel through PGAI, such as principle mechanism and data analysis method, which also has an important research value for promoting the application of PGAI technology.