SEISMIC ANALYSIS OF NUCLEAR REACTOR CONTAINMENT SHELL

Abstract

A nuclear containment shell is an axisymmetric. body consisting of a cylinderical structure resting on a raft and capped with spherical dome at tape . To prevent the leakage of radiations the wall thickness is kept large which results in a stiff structure These stiff structures are short time period structures and the influence of foundation, soil on the dynamic response of such, structures cannot be neglected A parametric study has been:_ carried out on a mathematical, model of nuclear containment shell to study the effect- of shear wave velocity;, soil extent , depth of embedement , soil damping •and type of earthquake .on.-.the dynamic response of. the shell when subjected to horizontal component of earthquake ground motion In this study .;it.has been observed that as the shear wave velocity increases the time period decreases At higher -shear wave velocityof 1500 m/s the structure behaves very nearly as. fixed base structure .'-Horizontal,displacement of the structure: decreases with the. increase in shear wave velocity.. The maximum- vertical normal stress follows no fixed pattern with the chang in shear .wave velocity- .There is a .definite extent of sail which can represent. the effects of infinite soil extent The embedded .structures are having lower time periods and these are seen to have smaller- stresses and displacements