A commonly used acronym by the NRC in their reports is the term SCRAM. While the use of the term is understood by many, the terms history is not so clear.
Source for full story:
http://public-blog.nrc-gateway.gov/2011/05/17/putting-the-axe-to-the-scram-myth/Quote:
According to Nyer, someone asked Wilson the reason for the red knob. Wilson replied you’d hit it if there was a problem. “Well, then what do you do?” he was asked. Wilson reportedly replied “You scram … out of here.” The word appears to have stuck.