If you hang out around nuclear reactors, SCRAM! means something different than it does other places. We’ll find out what nuclear engineers mean when they tell you to â€œScram it!â€? today on Engineering Works!
For nuclear engineers and reactor operators, the word â€œscramâ€? means something special. It means shut down the reactor – now. Every nuclear reactor in the United States has a big red button called the â€œscram button.â€? Push it and the reactor shuts down. But why â€œscram?â€? It all started with a guy with an axe standing on top of the first nuclear reactor ever built.
Scientists and engineers led by Italian physicist Enrico Fermi built it during World War II to do experiments that led to the first atomic bomb. Nobody knew much about how to control what was going on inside reactors. Fermi got an expert lumberjack to stand on top of the reactor with a big axe. The idea was that if something went wrong, the axeman would cut a rope that held up a big piece of cadmium metal. The cadmium would slam down inside the reactor and slow down the reaction enough to get it under control.
Fermi’s signal to the axe man was to shout â€œSCRAM!â€? – short for Safety Cut Rope Axe Man. The axeman never had to cut the rope. But he was ready.
Time’s up. Let’s SCRAM. We mean, get out of here.