Abstract
Fire safety is important throughout the lifetime of nuclear power plant (NPP), from design to construction throughout plant operation. The integrity of the shutdown cables located in the pump room in NPPs is very important in the fire protection system. Therefore, the present numerically study investigates the effect of outlet vent opening geometry and the location of the ventilation system specifications on the heat transfer in pump room during a fire. Three-dimensional ANSYS- FLUENT Computational Fluid Dynamics with Realizable k–ε turbulence model is employed in the present work. The results found that the geometry (aspect ratio) of the outlet opening vent has major effects on the shutdown cable protection from fire according to their locations. Furthermore, as the aspect ratio for outlet vent decreases, then the suction of hot gasses from the upper half of the room is improved. Consequently, the temperature of the heat source and target decreases. When the two inlet and outlet vents are located at a same lower level from the ground the inlet velocity should be 1.25 m/s, while, when the two vents are located at two different level the inlet velocity should be 0.75 m/s in order to protect the shutdown cable insulation.