SCRAM:
The first sustained nuclear chain reaction was accomplished At 9.45 on Dec. 2, 1942. This event, at the University of Chicago's squash courts under Stagg Field's bleachers known as Chicago Pile-1 (CP-1) was the birth of the term SCRAM.
The NRC, Fermi, Gollnick, and “Mr. Scram” himself - Dr. Norman Hilberry, doctor of physics (The actual SCRAM Tech) defines SCRAM as the Safety Control Rod Axe Man.
There is a reference that claims that Fermi used the term “Safety Cut Rope Axe Man” that also claims that they used a professional logger. This is a miss-quote. The Axe Man was a physicist named Dr. Norman Hilberry, who himself says that it stands for “Safety Control Rod Axe Man”.
Other legends contend that "Scram" is an acronym for "Start Cutting Right Away, Man", "safety control reactor axe man", “SuperCritical Reactor Axe Man”, “Safety Critical Reactor Ax Man “, “SuiCidal Reaction Axe Man “, “Shutdown Control Rod Axe Man”, “Secondary Control Rod Axe Man”, “Safety Control Reactor Axe Man”, “Safety Control Reserve Axed Man”, and “Safety Crew Reactor Axe Man” However, the term ‘reactor’ wasn’t even in use then, so those are probably backronyms.
http://www.orau.com/ptp/articlesstories/names.htm#scramhttp://www.ornl.gov/reporter/no19/scram.htmhttp://www.nrc.gov/reading-rm/basic-ref/glossary/scram.htmlhttp://users.owt.com/smsrpm/nksafe/forties.html
http://info.astrian.net/jargon/terms/s/scram_switch.htmlhttp://www.wowpage.com/tmi/core.htmlL. Marshall Libby The Uranium People, Crane, Russak & Co., 1979.
Gollnick page 44