BWR n 1: a nuclear reactor that uses water as a coolant and moderator; the water boils in the reactor core and the steam produced can drive a steam turbine [syn: {boiling water reactor}, {BWR}]
BWR \BWR\ n. a boiling water reactor; a type of nuclear reactor that uses water as a coolant and moderator; -- the steam produced can drive a steam turbine and produce electrical power. Syn: boiling water reactor. [WordNet 1.5]