Fluid-structure interaction (FSI) study on sodium leakage incident at prototype fast breeder reactor Monju by using ANSYS software

Fluid-structure interaction (FSI) is the interaction of movable or deformable structures affected by fluid flow surrounding and plays an important role in many issues related to the industry, especially in nuclear engineering. In a nuclear power plant system, the structures working under high pressure and temperature can cause excessive force or stress to the structures resulting in mechanical damages that may eventually threaten structural integrity. This research focuses on the investigation of sodium leakage incident issues at prototype fast breeder reactor Monju by using ANSYS simulation software. By using Modal and Fluent analyses in ANSYS, a comparison between the natural frequency of thermowell and vortex shedding frequency at several operation conditions has been done, and the most dangerous case was found for FSI analysis. The results of this analysis showed a stress concentration location similar to the location of broken thermowell and the amplitude of stress large enough for fatigue damage. (author)