B Reactor can take a tour of the reactor by advance reservation. The reactor was designed and built by E. I. du Pont de Nemours and Company based on experimental designs tested by Enrico Fermi at the University of Chicago, and tests from the X-10 Graphite Reactor at Oak Ridge National Laboratory. It was designed to operate at 250 megawatts (thermal). The reactor occupies a footprint of (about and is tall, occupying a volume of . The reactor core itself consisted of a graphite box measuring occupying a volume of and weighing . It was penetrated horizontally through its entire length by
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