MODELLING OF A STEAM LINE BREAK DURING AN EARTHQUAKE AND OF ITS EFFECT ON THE STEAM GENERATOR VVER 1000 SYSTEM

摘要

Dynamic effects of seismic excitation and of the steam line break in the weld of the steampipe and the steam collector during an earthquake are analyzed. Generated syntheticacceleration-time histories based on given floor response spectra are used to excite thesystem. To model the process of a circumferential crack evolution leading to the pressurizedpipe rupture and of the whip restraint function a special element in the programme SYSTUSis used. The stiffness and damping coefficients of this two node element may be defined asdependent on the relative displacement and velocity of its nodes. Whip of the steam line isanalyzed and its effect on the steam generator considered.