Analysis of Foreign Substance Flow within the Weld Joint through Simulation in Pressurized Water Reactor Nuclear Fuel Rods

Abstract

The welding of end plugs to cladding tubes is a critical process in the manufacture of pressurized water reactor (PWR) nuclear fuel rods. The resistance butt welding method is commonly used for this purpose in production. In this paper, we present an analysis of the flow of foreign substances within the weld joint during the tube-cap welding process of PWR nuclear fuel rods, using SORPAS 2D software. The welding process generates foreign substances such as oxide scales, welding fumes, and spatters, which can negatively impact the quality of the weld. Additionally, carbide-based ceramic materials with higher melting temperatures than the base metal have been found within the weld joint in some cases, which can also affect the quality of the weld. To simulate the intrusion of foreign substances with higher melting temperatures than the base material (zirconium alloy) during welding, we conducted a simulation and analyzed the flow of foreign substances. Based on this study, we expected to enhance the reliability and stability of the tube-cap welding process of PWR nuclear fuel rods.