The possibilities of using high-temperature reactors operating together with a gas turbine are determined for nuclear-powered icebreakers. The advantages of such systems over previously used nuclear-powered systems and diesel-electric propeller systems are examined. The possibilities of using the MARS-S reactor and gas-turbogenerators, utilizing the heat from the exhaust gases, in nuclear-powered icebreakers are studied. The characteristics of the MARS-S and propeller electric system of a nuclear-powered icebreaker with drive-shaft power up to 90 MW are presented. The possibility of using such systems in floating electric power plants utilizing heat for driving a counterpressure turbine is examined. A version of a single-reactor ship power plant for a lighter and an icebreaker, such as Taimir, is presented.