Last Updated: Jun 2011
What is it?
Nuclear power is energy which is produced with the use of a controlled nuclear reaction. Interest in marine nuclear propulsion has been driven partly by increasing pressure on the shipping industry to reduce its carbon dioxide.
Nuclear marine propulsion is propulsion of a registered ship class by a nuclear reactor. Marine reactors differ from commercial reactors in that they are compact but produce significant power in a small volume. Marine reactors are designed for a long core life.
Unlike commercial nuclear power plants, reactors onboard a vessel must be rugged and resilient enough to withstand rigourous operations at sea, subject to a ship's pitching and rolling and rapidly-changing demands for power, and for Navy ships possibly under battle conditions.
How it works
The process of generation nuclear power starts with the mining and processing of uranium deposits found in rocks.
The nuclei of uranium, when bombarded with neutrons, split into simpler nuclei. This breakup of radioactive nuclei, called nuclear fission, accompanies enormous amounts of nuclear energy.
The nuclear fission process takes place in a vessel called nuclear reactor. The heat released during fission is transferred to a water boiler via a heat-transfer fluid or reactor coolant. The heat contained in hot coolant converts the water in boiler tube to high pressure steam. The steam generated in boiler passes through a steam turbine thus making it turn.
The steam is then used to drive turbines that generate electricity.
In the case of nuclear submarines, nuclear reactors, steam turbines and reduction gearing are used to drive the main propeller shaft, which provides the forward and reverse thrust in the water.
Onboard a vessel steam supplies the energy required to drive the turbine generators. The turbine generators then cause the propeller to rotate thereby causing thrust and a forward motion to the ship.