75 years of science and technology
Two events in 1938 proved critically important to the course of World War II. In the first, German chemists Otto Hahn and Fritz Strassmann discovered nuclear fission. In the second, Italian physicist Enrico Fermi and his Jewish wife, Laura, left their home to avoid Italy’s new Racial Laws.
The couple’s decision to emigrate was a boon to the United States. Fermi picked up a Nobel Prize in Physics in Sweden that year, but rather than return to Italy, he traveled on to New York, where he took a position at Columbia University.
He also became a key player in the Manhattan Project, leading the team that created the first nuclear fission reactor, named Chicago Pile-1.
More than 385 tons of graphite and 46 tons of uranium fuel went into the pile, which was built on a rackets court beneath Stagg Field on the campus of the University of Chicago.
Forty-nine scientists and workers gathered for its momentous start-up on December 2, 1942. Most watched from a balcony while Fermi directed scientist George Weil to carefully remove the cadmium rods that had been preventing a chain reaction. The occasion included a lunch break, after which Fermi instructed Weil to pull the last control rod out another foot.
The clacking of neutron counters verified that the reactor had indeed “gone critical,” or sustained a nuclear chain reaction. That reaction lasted less than five minutes before the reactor was shut down. The group celebrated its achievement with a bottle of Chianti, provided by future ORNL R&D Director (and physics Nobelist) Eugene Wigner.
