The paper deals with mathematical modelling and computer simulation of the seismic response of chosen components of hte nuclear WWER 1999 reactor. The seismic response is investigated by numerical integration method in time domain. The seismic excitation is given by two horizontal and one vertical synthetic accelerograms at the level of the pressure vessel seating adjusted for a certain damping vallue 5 %. The main aim of the paper is seismic response assessment for two variants of nuclear fuel assemblies - VVANTAGE 6 and TVSA-T. The maximal values of displacements and linkages or component deformations are compared for both fuel assembly variants. and Obsahuje seznam literatury