Analysis of relative motion between PWR pressure vessel and its internals

A mathematical model is analyzed describing the relative motion of the PWR pressure vessel and core vessel. The actual system of exciting forces may be replaced by a linear discrete dynamic model with four axially asymmetrical solid bodies linked with four springs. In rated operation pressure fluctuations in the coolant flow and those due to main circulating pump operation affect the reactor internals. The IDENT program written in ALGOL developed for practical calculations using the model is briefly described. (Z.M.)