<b>Nuclear Propulsion</b> In a ship with nuclear propulsion, a chain reaction of nuclear fission processes is generated in a reactor. The resulting heat is used to generate steam to drive a steam turbine. The advantage of this drive lies in the lower fuel requirement and an almost unlimited radius of action of such a ship. The high costs of building, operating, maintaining and disposing of such ships have proven to be disadvantageous. Added to this is the danger to the environment from escaping radiation that can never be ruled out, up to and including the contamination of extensive sea and port areas when a reactor accident occurs. The world's first nuclear-powered merchant ship was launched in 1962 by the American “Savannah”. It was only after long disputes about the safety precautions to be taken that “Savannah” was allowed to cross the Atlantic for the first time in June 1964. The service life of the ship was only 7 years, then it was launched. The operation had simply proven to be too expensive. A German merchant ship named after the chemist Otto Hahn, who discovered nuclear fission in uranium in 1938, was put into service in 1968. The ship was designed as an ore freighter and, with a length of 162 m, a width of 23.4 m and a draft of 9.2 m, had a carrying capacity of 15,000 dwt. The speed was almost 16 knots, the power of the steam turbine 10,000 hp . On board were 73 crew members plus 26 people who did “reactor research”. The "Otto Hahn" drove for 10 years without any significant problems. Nevertheless, the ship was decommissioned in 1978. The nuclear disposal of the ship took 3 years. This resulted in costs of more than DM 20 million. Later the “Otto Hahn” was converted into a container ship and received a diesel engine. With that the time of the nuclear powered merchant ships was over. Furthermore, in today's much more environmentally conscious times, nuclear-powered merchant ships would probably have greater problems obtaining access permits for trading ports. In this respect, this propulsion method is now reduced to naval vessels, especially submarines.