[en] This paper describes the principles and examples of applications of an explicit Lagrangian coupled finite difference-finite element code HEMP-ESI developed in order to calculate the structural consequence of hypothetical core disruptive accidents (HCDA) in nuclear reactors. Two examples of simulation show the applicability of the method to nuclear reactor core safety analysis (test problem): 1) core explosion in a loop-type reactor including a shell containment. The calculation shows the energy absorbing function of the shell and enables the evaluation of the forces acting on the reactor containment. 2) Hypothetical Core Disruptive Accident in a fast breeder reactor. The calculation shows the main features of this accident. (Auth.)