December 2: It’s a double milestone for nuclear energy. The first man-made sustained nuclear chain reaction was created this day in 1942. And just 15 years later, the first full-scale nuclear power plant went online.


1942: Enrico Fermi, Leo Szilard and their colleagues achieve a successful, controlled chain reaction in a squash court underneath the football grandstand of the University of Chicago’s Stagg Field. It lays the groundwork for the first atomic bombs.


Fermi and Szilard had been working on nuclear fission at Columbia University in New York, when Albert Einstein wrote of their work to President Franklin D. Roosevelt. Einstein feared that German nuclear researchers might gain an unbeatable lead in the field and develop an atomic weapon that could win the war.


The Roosevelt administration responded with the then-secret, now-famous Manhattan Project. Top U.S. atomic scientists soon gathered in Chicago to see just how feasible it was to start a nuclear chain reaction, starting with a controlled rather than explosive one.
The original idea was to build a nuclear pile at a location in the Argonne Forest about 30 miles outside Chicago, but there were construction problems. Remarkably, the experiment was relocated to the University of Chicago campus inside city limits.


Construction began Nov. 16, 1942. The team got uranium from an Iowa State University researcher and Westinghouse Electric. Staffers worked around the clock to build a wooden structure on which they placed a lattice of 57 layers, comprising six tons of uranium metal and 40 tons of uranium oxideembedded in 380 tons of graphite blocks.
The whole apparatus was encased in a custom square balloon built by Goodyear Tire. The Chicago Pile-1 cost $2.7 million (about $36 million in today’s money).


The Dec. 2 experiment began at 9:45 a.m. with more than 50 people in attendance. A three-man “suicide squad” was ready to douse the reactor in case it threatened to get out of control. Besides the main On/Off switch, there was a weighted safety rod that would automatically trip if neutron intensity got too high, a hand-operated backup safety rod, and “SCRAM” — the safety control rod ax-man, a top staffer wielding an ax to cut a rope to drop the safety rod, if all else failed.


The suicide squad wasn’t needed. The pile achieved a sustained nuclear reaction at 3:25, and Fermi shut it down at 3:53. Those 28 minutes changed the world.


So secret was the project that at a party a few days later, the scientists’ spouses didn’t know what the all the congratulations were about. They wouldn’t find out what had happened and where the technology was headed for another two-and-a-half years. And then, the world knew.


1957: The light-water breeder reactor at Shippingport, Pennsylvania — the first in the United States — goes to full power on the anniversary of Chicago Pile-1.

An experimental breeder reactor devised by Chicago Pile-1 veteran Walter Zinn had created the first nuclear-generated electricity in 1951, and the Soviets opened a small nuclear power plant in 1954. President Dwight D. Eisenhower broke ground that year for the first full-scale commercial plant, to be operated by Pittsburgh’s Duquesne Light Co.
Westinghouse Electric designed the plant in conjunction with the Atomic Energy Commission. When it was in operation, nuclear fission heated water, which transferred its heat to convert the water in a secondary system into steam, which drove the turbine that created the electricity.


Shippingport shipped its first power into the Pittsburgh grid Dec. 18, 1957. Eisenhower returned to formally dedicate the plant the following May 26.


The plant was decomissioned in 1982 after a quarter-century of use. In the first complete U.S. decontamination, the reactor vessel was shipped to a low-level waste disposal facility at the Hanford Site in Richland, Washington.


After the Shippingport site was cleaned, the government released it for unrestricted use in 1987, suitable for picnicking or a children’s playground. The American Society of Mechanical Engineers designated the plant as a landmark, and it’s now open to visitors.