Scram as the original and mostly likely accurate basis for the use of scram in the technical context. A persistent alternative explanation posits that scram is an acronym for 'safety control rod axe man', which was supposedly coined by Enrico Fermi when the world's first nuclear reactor was built under the spectator seating at the University of Chicago's Stagg Field. It could also stand for "Safety Control Rods Activation Mechanism" or "Control Rods Actuator Mechanism". Both of these are probably backronyms from the original, non-technical usage. In any reactor, a SCRAM is achieved by inserting large amounts of negative reactivity mass
Enrico Fermi Nuclear Generating Station of threats to public health and the environment. The groups have filed 14 contentions with the NRC, claiming that a new plant would pose "radioactive, toxic and thermal impacts on Lake Erie's vulnerable western basin." In May 2015, the Nuclear Regulatory Commission approved a combined construction and operating license for Fermi 3, but DTE Energy stated there were no plans for construction at that time. The Nuclear Regulatory Commission's 2010 estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Fermi was 1 in 238,095 making it the 88th least likely