LIGHT WATER REACTOR (LWR)

A nuclear power plant which uses ordinary Water (H2O) as distinguished from one that uses Heavy Water (D2O) or Deuterium Oxide. Fission energy is released in the form of heat and is transferred to a conventional steam cycle which generates electric energy. Heat generated by the fission of the uranium fuel raises the temperature of the water, which is then pumped to heat exchange units for the production of steam and subsequent generation of electricity. The process results in a continuous transfer of heat from the reactor to the outside. The water also functions as a moderator to reduce the energy level of neutrons released by the fission process in order to allow the neutrons to promote additional fission events. The light-water reactor is the most common type of nuclear reactor operated in the United States.