Enrico Fermi Enrico Fermi Enrico Fermi (; ; 29 September 1901 – 28 November 1954) was an Italian and naturalized-American physicist and the creator of the world's first nuclear reactor, the Chicago Pile-1. He has been called the "architect of the nuclear age" and the "architect of the atomic bomb". He was one of very few physicists to excel in both theoretical physics and experimental physics. Fermi held several patents related to the use of nuclear power, and was awarded the 1938 Nobel Prize in Physics for his work on induced radioactivity by neutron bombardment and for the discovery of transuranium elements.
Shutdown (nuclear reactor) Shutdown (nuclear reactor) In a nuclear reactor, shutdown refers to the state of the reactor when it is subcritical by at least a margin defined in the reactor's technical specifications. Further requirements for being shut down may include having the reactor control key be secured and having no fuel movements or control systems maintenance in progress. The shutdown margin is defined in terms of reactivity, frequently in units of delta-k/k (where k is taken to mean k-effective, the effective multiplication factor) or occasionally in dollars (the dollar is a unit equal to the change in reactivity needed to go from