Thermal-Hydraulic analysis of plate-type fuel has a greatimportance to the establishment of safety criteria, also to the licensing of the future nuclear reactor with the objective of propelling the nuclear submarines (SSN). As a starting point, this work has performed an analysis of a single plate-type fuel surrounded by two water channels. The fuel was assumed to be made of uranium dioxide UO2 sandwiched between two Zircaloy-4 plates. The simulations are carried out by using the RELAP5 (Reactor Loos of Coolant Accident Program) to solve the equations of the theoretical model. Also a CLOFA (Complete Loss of Flow Accident) was simulated to show the behavior of the model in a severe type of accident. The results show that the CHFC (Critical Heat Flux Condition) was reached in the system and the maximum CHF (Critical Heat Flux) was detected in the central region of the plate.