A research in the inspection of girth weld of neptunium fuel rod in the fast reactor

The fast reactor is the preferred reactor type, which represents the development direction of the fourth generation of the advanced nuclear energy system. To acquire advanced nuclear fuel assembly manufacture technology, our company launched a research about assembly and manufacture of the fast reactor fuel cooperating with China Institute of Atomic Energy. The fuel rod is the core component in the reactor. The quality of the weld between the cladding and the end plug directly affects the service life of the fuel rod and the safe operation of the nuclear power. Non-destructive testing technology is particularly important, in order to ensure the quality of weld inside the fuel rod. X-ray technology is used in the inspection of the fast reactor fuel rod. The paper study the technology of the X-ray inspection of girth weld in neptunium fuel rods. It focused on selecting the appropriate radiography mode, calculating the availability radiography area, designing and manufacturing compensation block and exploring the technological parameter. Through the study in process, It finally found the inspection method to guarantee the inside quality of the girth weld in the fast reactor of neptunium fuel rod. And it reached the following conclusions: The radiographic inspection technological parameter of the girth weld in the neptunium fuel rod is identified with full compensation radiography; the study found the technological parameter of neptunium fuel rod; it can be used to inspect the quality of girth weld inside of the neptunium fuel rod, as it can be used to detect whether the fuel rod is flawed. (authors)