This article presents the parametric study of pull-out radius of steam generator shell nozzle junction for fast breeder reactor. An efficient finite element modeling for shell nozzle junction has been presented in which shell elements are employed to idealize the whole region. In shell nozzle junction, pull-out region is an important part, so that region is taken and studied with different radius of curvature. The pull-out radius varies from 40 to 80 mm. Five models are taken into consideration and each with different radius of curvature. The optimized stress values for all the models are presented here.