This paper, brought out the conservatism involved in predicting the crack initiation of the full scale large size pipe bend using nuclear class-1 piping design philosophies against the full scale testing. French class-1 nuclear piping design standard, RCCMR RB 3600 [1] has been used for predicting the fatigue life of the typical critical piping product in the sodium heat transport system of the Sodium cooled Fast Reactors (SFR). Numerical simulation has been carried out towards the life prediction. Salient features of the computational model, experimental simulations of deformation controlled cyclic displacements and comparison of the full scale test results with the design standard are presented in this paper. © 2017 Chinese Society of Theoretical and Applied Mechanics. All Rights Reserved.