Nuclear Reactor

A nuclear reactor is a device built to sustain a controlled nuclear fission chain reaction, used to generate electricity, power ships, produce material for weapons, and support scientific research. Inside the reactor, fissile nuclei such as uranium-235 or plutonium-239 absorb neutrons and split into lighter elements, releasing energy and further neutrons that can trigger more fission events; operators keep the chain reaction at a safe, steady rate using neutron-absorbing and moderating materials in the core. The first artificial reactor, Chicago Pile-1, achieved criticality on December 2, 1942, at the University of Chicago, built under the wartime Manhattan Project from graphite blocks and natural uranium oxide stacked in a pile supported by a wooden frame. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/