Nuclear power has been used for ship propulsion since the 1950s when the first nuclear powered submarine was launched. Since then numerous warships like cruisers and aircraft carriers have been built with nuclear propulsion in countries like the US, France,Russia, Britain. This propulsion system has the advantage of not requiring regular refueling as refueling is carried out on nuclear powered vessels once every twenty years. This saves a lot of money that obviously would have been spent refueling these vessels if they were running on conventional fuels like diesel. Plans are now well underway to build merchant vessels with nuclear propulsion to reduce the cost of refueling and to prevent damage to the environment due to oil spill from ships which could occur during accidents or bunkering. These vessels equipped with nuclear power can sail with unlimited ranges and would not require refueling at any port of call and so saves time and money for the companies operating these vessels.