Nuclear-powered cargo vessels

 Soon after the dawn of the nuclear age in 1945, eyes and minds turned to the possible peaceful uses of nuclear energy.  Nuclear plants for production of electricity gradually became common.  Use of atom bombs for large construction projects, such as a second canal between the Atlantic and Pacific, were proposed, but quickly shelved.  One experiment that went forward, though, was construction of cargo vessels powered by nuclear reactors.  The science was not new, as nuclear-powered submarines and warships had led the way and proven the technology.  In those heady days, it was envisioned that there would be large savings in fuel costs, as the new ships could operate for years before the nuclear rods would need replacing.  Four such cargo ships were built.  The first down the ways was the NS Savannah, launched by the United States in 1959.  It was built to carry up to 60 passengers and about 14,000 tons of cargo.  While the propulsion system was state of the art, the cargo system was old-fashion break bulk.  It had a crew of 124, making its operating costs extremely high.  It was followed in 1968 by the German ore carrier Otto Hahn.  In 1970, the Japanese freighter Mutsu was launched.  On its first test voyage, a small leak of neutrons and gamma rays led to major public protests.  The Russian cargo ship Sevmorput was put into service in 1988.  Due to high operating costs and public concern about nuclear-powered ships calling in civilian ports, all four ships have failed to live up to expectations.  The Savannah was decommissioned in 1972 and awaits scrapping.  The Otto Hahn was converted to diesel power in 1979.  It was finally scrapped in 2009.  The Mutsu was converted to diesel power in 1995 and now operates as an ocean observation vessel.  The Sevmorput still has its nuclear reactor, but has been out of service since 2007, awaiting possible conversion into an oil drilling vessel.  Nuclear power for non-military vessels has proven to be viable only for the niche activity of ice breaking.  The Russians built seven ocean-going nuclear-powered icebreakers (the most powerful icebreakers in the world) and two nuclear-powered river icebreakers.  Three of the Russian icebreakers have been decommissioned or otherwise taken out of service.