NS Savannah was the first nuclear-powered merchant ship. She was built in the late 1950s at a cost of $46.9 million and launched on July 21, 1959. She was funded by United States government agencies. Savannah was a demonstration project for the potential use of nuclear energy. The ship was named after SS Savannah, the first steamship to cross the Atlantic ocean. She was in service between 1962 and 1972 as one of only four nuclear-powered cargo ships ever built.

Nuclear marine propulsion is propulsion of a ship or submarine with heat provided by a nuclear reactor. The power plant heats water to produce steam for a turbine used to turn the ship's propeller through a gearbox or through an electric generator and motor. Nuclear propulsion is used primarily within naval warships such as nuclear submarines and supercarriers. A small number of experimental civil nuclear ships have been built.