核反应堆 héfǎnyìngduī nuclear reactor Origin Definitions Defs Strokes Stroke Words Sentences Sents 原子核反应堆 yuánzǐhéfǎnyìngduī nuclear reactor a device used to initiate and control a self-sustained nuclear chain reaction to produce energy or isotopes热核反应堆 rèhéfǎnyìngduī thermonuclear reactor A device used to initiate and control a nuclear fusion reaction; also known as a thermal reactor.