Abstract: An integrated pressurized-water reactor and steam generator is disclosed, particularly for ship propulsion and smaller stationary installations, in which circulating pumps of primary coolant loops are arranged in the upper part of a vertical pressure vessel close to the vessel's removable head. An annular steam generator is arranged centrally within the vessel, and above the outer periphery of a reactor core in the vessel's lower portion, and is suspended via a separate hollow ring supported by the vessel's upper portion and in which the impellers of the circulating pumps are arranged. The primary cooling water flows upwardly through the reactor core and the heat exchanger to the pumps located above, and from there, through a separate ring passage outside of the heat exchanger housing and core downward to again flow upwardly through the reactor core.