[en] The susceptibility of the primary coolant boundary components of the 300-MW(e) gas-cooled fast breeder reactor (GCFR) demonstration plant to flow-induced vibrations is analyzed. This preliminary analysis is based on the 1974 reference design. Many design changes have been proposed, but this report examines only the instrument tree design. This study shows that the analytical models developed so far can be used only for the most simple systems, and they have a very limited value for the often complicated primary coolant boundary components. The highly turbulent flow field further complicates the analysis. The results, however, provide an understanding of the basic parameters and some insight into the most vulnerable components as well as ways and means to avoid problem areas. Some general guidelines which can be used in the early stages of the design to avoid or minimize the probability of flow-induced vibrations are presented. It is recommended that the assembly locking mechanisms be eliminated and other means of locking the assemblies to the grid plate be used. These should be less susceptible to flow-induced vibrations. The number of radial support plates for the steam generators should be increased from 4 to 6 to avoid whirling