การพัฒนาระบบมองภาพทนรังสีสูงสำหรับงานตรวจสอบใต้น้ำควบคุมระยะไกล / สมาน อิงไธสง = Development of a high radiation resistant visualising system for under water remote inspection / Saman Ingtaisong
This research aimed to develop an economical high radiation resistant visualizing system for periodic underwater inspection of spent fuel elements of the Thai Research Reactor-1/Modification 1. The structural design was intended to have compact size and light weight. The small size, low radiation response, digital CMOS color CCTV camera with image resolution of 2 Megapixels and USB port interface to display on computer was selected. Hot pixels occurring from radiation effect on the image sensor which interfere the video image background was reduced by lead shielding and mirror reflection viewing to prevent direct exposed to the camera. Appropriate size of lead shield was designed by using computer codes i.e., ORIGEN-S for fission product inventory calculation and MCNPX for shielding design using the source term from the ORIGEN-S calculation. From this development, a high radiation resistant visualizing system with the dimension of 11.5 x 11.5 x 18.0 cm and 10 kg in weight was achieved and it was capable to operate under 5 m deep water without water leakage. From the observation of image quality, small defect and marking number of 0.4 cm size on the fuel element could be detected by visual inspection. By employing 2 cm camera lead shield, the operation at 160 mGy/h dose rate found the hot pixel area of 0.012%. Besides, the system could be also applied for other high level operations.