Argonne at 50

Patent on world's first reactor was a long time coming

ARGONNE, Ill. (May 18, 1996) -- Their names are the stuff of legend: Eli Whitney, Samuel Morse, Alexander Graham Bell, Enrico Fermi. Their inventions -- the cotton gin, the telegraph, the telephone, and the nuclear reactor -- have been compared to the discoveries of fire and the wheel in their impact on human history.

The Italian-born Fermi and his team of scientists at the University of Chicago's Metallurgical Laboratory -- predecessor to Argonne National Laboratory -- ushered in the nuclear age when they achieved the world's first controlled, self-sustaining nuclear chain reaction on December 2, 1942. But getting a patent on their historic invention turned out to be nearly as difficult as the breakthrough itself.

Within three months, Fermi's reactor had been moved to the Met Lab's new "Argonne Laboratory," so named because it resided what was then called the Argonne Forest section of the Cook County Forest Preserve in Palos Park.

Fermi, the first director of the Argonne Laboratory, had received the 1938 Nobel Prize in physics for his discovery of transuranic elements (man-made elements heavier than uranium) and his work on the effect of slow neutrons on nuclear reactions. In 1934, he had achieved nuclear fission without realizing it during experiments on neutron bombardment.

One member of Fermi's Met Lab team was the Hungarian-born scientist Leo Szilard. Two years after the 1932 discovery of the neutron, Szilard, then living in England, had applied for a patent for his concept of a nuclear chain reaction. His theory, which he kept secret, did not, in fact, prove practical.

Physicist Rudolph Peierls described Szilard's penchant for invention in these words:

"He was a physicist with a very original mind and a flair for invention. He held several patents, but I do not know whether any of them ever proved commercially viable. Almost as soon as the neutron was discovered, he thought of the possibility of a nuclear chain reaction and of its potential dangers. In 1934 he filed for a patent that described the laws governing such a reaction. For some reason, however, he also had the misguided idea that a chain reaction might be possible in lithium."

Research on atomic fission continued rapidly during the 1930s, but accelerated in the early 1940s as the United States geared up to beat Nazi Germany -- which had unknowingly achieved uranium fission in 1939 -- to the first atomic bomb.

In 1942, Fermi, Szilard and their émigré and American colleagues worked at breakneck speed in utmost secrecy. Work on the first reactor, called Chicago Pile 1, under the West Stands at the University of Chicago's Stagg Field was kept so secret that even Fermi's wife did not learn of it until mid-1945.

Work on the initial patent application had begun six months before the reactor was completed. And as the U.S. reactor program expanded over the next two years, so did the application. Ultimately, it included Chicago Pile 1, Chicago Pile 2 (the name given CP-1 after its move to Palos Park), the prototype reactor at Clinton Laboratory (the forerunner of today's Oak Ridge National Laboratory in Tennessee), and finally the production reactors at Hanford, Wash.

The highly classified patent for the first atomic pile was filed with the U.S. Patent Office in December 1944. It listed Fermi and Szilard as co-inventors and described the method by which a self-sustaining nuclear chain reaction had been achieved.

The patent -- number 2,708,656 -- was finally issued on May 18, 1955 -- 13 years after it had been started and nearly 11 years after it had been filed.

By then, Fermi had been dead for six months.

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For more information, please contact Steve McGregor (630/252-5580 or media@anl.gov) at Argonne.