Research On Deformation Size Detection System Of Nuclear Fuel Assembly Based On Underwater Camera

Fuel assembly is the core component of PWR core.The quality of the fuel assembly is the guarantee for the safe operation of the nuclear power plant.Therefore,before the fuel assembly is put into use,the detection of the fuel assembly shape is an effective technical means for quickly judging whether the fuel assembly can be normally returned to the irradiation test.People need to develop a more accurate detection system to accurately measure the fuel assembly shape and size changes.Due to the influence of water on light absorption and scattering,the contrast and clarity of underwater images are low and some problems such as color bias appear.Therefore,the study of underwater image enhancement technology is the key to obtain clear and high-quality images and is helpful to detect and identify the target in the image.It is very important in the process of fuel assembly shape and size detection.Based on the hardware design of underwater nuclear fuel assembly size detection system and the image clarification processing of software system,this paper studies the problems encountered in the measurement of underwater nuclear fuel assembly shape size.Aiming at the key problems encountered in the measurement process,a measurement system suitable for fuel assembly shape and size detection is designed.The accuracy and stability of the software system are simulated and verified by virtual simulation technology,and the AFA-3G fuel assembly is experimentally verified by repeated measurement method.In this paper,we choose the combination of halogen lamp and LED lamp to provide light source,and use high-definition color camera to collect underwater fuel assembly images,and propose an image quality enhancement algorithm based on Laplacian pyramid fusion to clarify the acquired fuel assembly images.Finally,we obtain high-quality and clear images.In this paper,a software system for fuel assembly dimension detection is developed by using LabVIEW and MATLAB software.In the software system designed in this paper,the height of fuel assembly is measured by the method of scale calibration.A series of algorithms of image preprocessing are used to extract the center line of fuel rod for rod spacing measurement.The shoulder spacing,bending and twist of fuel assembly are measured by the method of picking up the pixel value.The research results show that the fuel assembly size detection system proposed in this paper meets the requirements for measuring the dimensional change of fuel assemblies.