The preliminary structural analyses for an advanced burner test reactor (ABTR) internal structure are performed with regard to the elevated temperature design and the seismic design. In the elevated temperature design, three load cases enveloped from ABTR duty cycle events are studied for the structural integrity evaluation according to the ASME-NH design rule. The resulting stresses and strains are compared with the allowable design and service limits. An elastic approach, a simplified inelastic approach and a creep fatigue analysis are performed to provide a quantitative assessment of the deformations and strains. In the seismic design, the response spectrum analyses including the fluid-structure interaction effect are performed for isolated and non-isolated conditions. From the evaluation results, it is found that the seismic isolation capable of reducing the seismic input transmitted to the foundations is needed to satisfy the allowable design limits. For the isolated condition, three design cases for the variation of the wall thickness as 1.5 cm, 2 cm and 3 cm are studied for the design modification.