nuclear reactor
nuclear reactor, device for producing NUCLEAR ENERGY by controlled nuclear reactions. It can be used for either research or power production. The reactor is so constructed that the fission of atomic nuclei produces a self-sustaining nuclear chain reaction, in which the produced neutrons are able to split other nuclei. A fission reactor consists basically of (1) a fuel, usually uranium or plutonium, enclosed in shielding; (2) a moderator--a substance such as graphite, beryllium, or heavy water--that slows down the neutrons so that they may be more easily captured by the…
