A numerical methodology is developed and established using a 1D plant dynamic network model against the benchmark test of the Superphenix French sodium-cooled fast reactor (SPX). The accuracy of the simulation performed by the PINET (PIpe NETwork) code has been verified. In the SPX benchmark, a total of six transient models were provided. The current research focuses only on the thermal hydraulics side of those transient models. The neutron Kinetics was taken as input to the model in this study. Within the scope of this study, the transient benchmark was solved utilizing the PINET code. The obtained numerical results have been compared to the existing measured data, demonstrating satisfactory agreement. The reasons behind specific disparities have been adequately elucidated.