The direct-contact condensation (DCC) is a significant phenomenon in a nuclear reactor and its balance facilities, together with some chemical engineering systems. DCC occurs when the vapor is ejected from the nozzle, contacts with subcooled water, and condenses at the interface directly. The DCC phenomenon accompanied with the heat transfer and mass transfer will lead to the temperature and pressure fluctuations in the tank, even some accidents under certain conditions. This paper investigates the transport phenomena concerning the DCC in the subcooled water tank using the computational fluid dynamics (CFD) commercial code, ANSYS-FLUENT, in which the DCC process is simulated with the Euler–Euler framework for two-phase flow, and the simplified Hertz–Knudsen–Schrage relation is adopted to model mass transfer. In the simulation, the flow field and temperature profile are derived. Moreover, the shape and size of the plume jet are also investigated.