[en] The preliminary dynamic analysis of the GCFR core support structure including the effects of the core elements is reported. The basic approach assumes the core support structure, i.e., the grid plate and its support cylinder, and the core elements to be represented as axisymmetric linear structures. The response of such axisymmetric bodies when subjected to asymmetric loadings may be determined by representing the circumferential variation of the load and the response as a Fourier series, solving for each harmonic separately, and using linear superposition to combine the results. This is an accurate representation of the grid plate and its support cylinder, but is only approxmately valid for the core elements. Time history response is provided for three assumed site conditions