WATER-COOLED REACTOR

A nuclear reactor that employs water to cool the reactor core. A nuclear reactor is a device designed to promote the fission of an appropriate fuel (such as uranium-235) in a controlled manner. The heat produced during the fission event must be removed from the device to prevent an excessive buildup. Water is usually used as the heat transfer agent. Other coolants used in nuclear reactors of other designs are liquid sodium and inert gases. Also see Light Water Reactor (LWR).