Study on Indirect Neutron CT Technology of Nuclear Fuel Element Based on Neutron IP Plate 基于中子IP板的核燃料元件间接中子CT实验方法研究

Neutron radiography, an effective non-destructive testing technology, is an important means to analyze and determine the defects inside nuclear fuel elements. Based on the neutron radiography platform located at China Advanced Research Reactor (CARR), the neutron radiography group at China Institute of Atomic Energy has carried out the research on the simulated nuclear fuel elements using the developed indirect three-dimensional neutron imaging device for nuclear fuel elements. The key parameters of sample transfer container for nuclear fuel elements were optimized and the container was designed based on the Monte Carlo simulation method. As a result, the study on simulated sample of nuclear fuel elements was performed using the developed indirect three-dimensional neutron imaging device, and the defects with the size of about 0.35 mm can be clearly observed in the obtained reconstructed 3D images. Therefore, the experimental results indicate that this developed device at CARR can meet the demand of studying nuclear fuel elements. Besides, several factors and processing methods for indirect neutron CT experimental digital images during data processing were also studied simultaneously, and this study can provide some invaluable advice for practical application of real nuclear fuel elements using metal conversion screen to replace the neutron image plate (IP) in this study in future.