How the First Chain Reaction Changed Science
Source Newsroom: University of Chicago
Newswise — The Atomic Age began at 3:25 p.m. on Dec. 2, 1942—quietly, in secrecy, on a squash court under the west stands of old Stagg Field at the University of Chicago.
Today, Henry Moore’s “Nuclear Energy” sculpture and the Mansueto Library occupy the area at the corner of Ellis Avenue and 57th Street where Enrico Fermi and his colleagues engineered the first controlled, self-sustaining nuclear chain reaction 70 years ago. Their experiment was a key step in the Manhattan Project to develop the atomic bomb during World War II.
That initial chain reaction was too weak to power even a single light bulb. It nevertheless transformed the world, and the University of Chicago along with it, in a range of endeavors spanning physics, chemistry, interdisciplinary research, policy analysis, and nuclear medicine. Even in 1942, those present at the historic event sensed how influential their work would be.
“All of us . . . knew that with the advent of the chain reaction, the world would never be the same again,” former UChicago physicist Samuel K. Allison wrote at the time.
That first chain reaction’s complex legacy includes the peaceful uses of nuclear energy, the terrible power of nuclear weapons, and a new era of other scientific and technological advances.
After the war, UChicago founded the Institute for Nuclear Studies and the Institute for the Study of Metals. Later renamed the Enrico Fermi and the James Franck institutes, they enabled the University to retain much of the intellectual talent that had assembled on campus to work on the Manhattan Project. Another outgrowth of the project was Argonne National Laboratory, which conducts basic and applied research in many major scientific disciplines. Today, Argonne is a partner in the Institute for Molecular Engineering, which is bringing leading scientists and engineers to a groundbreaking initiative to conduct research at the molecular level.
“What we see here is a legacy of connection that we’re still building upon, a way to try to redefine engineering for the 21st century," said Provost Thomas Rosenbaum, the John T. Wilson Distinguished Service Professor in Physics.
Building the pile
Though Fermi’s team was engaged in the biggest secret project of World War II, they discussed technical issues under a tree on the Main Quad, which they deemed safe from eavesdroppers. In the middle of the day on which they produced the first chain reaction, they took a customary lunch break at Hutchinson Commons.
“Don’t imagine that they were able to achieve a chain reaction on the first try,” says Roger Hildebrand, the Samuel K. Allison Distinguished Service Professor Emeritus in Physics. “They built and rebuilt stacks of uranium, uranium oxide, and graphite 30 times before they were ready for the final test.”
Chicago Pile Number One, or CP-1 for short, consisted of 40,000 graphite blocks that enclosed 19,000 pieces of uranium metal and uranium oxide fuel. The scientists of what was then called the Metallurgical Laboratory, or “Met Lab,” had arranged the graphite in layers within a 24-foot-square wooden framework.
Hildebrand had started his work on the Manhattan Project as an undergraduate chemistry major at the University of California, Berkeley. He worked for Nobel laureate Ernest Lawrence, namesake of the Lawrence Livermore and Lawrence Berkeley national laboratories, using Berkeley’s cyclotron accelerator to transmute uranium into plutonium, an element believed to have potential for driving a chain reaction.
The samples irradiated in Berkeley and another lab in St. Louis ended up in the James Herbert Jones Laboratory, just one block south of old Stagg Field. There, in Jones Lab’s Room 405, future Nobel laureate Glenn Seaborg achieved an important steppingstone on the way to the Atomic Age. He weighed the first visible, pinhead-sized sample of plutonium. It wasn’t much, but enough to measure its chemical and metallurgical properties.
The potential hazards of nuclear power were evident even in those early days, but the war effort took priority. The Japanese had bombed Pearl Harbor on Dec. 7, 1941. Germany and Italy declared war on the United States four days later.
“They were advancing everywhere, they were conquering everywhere, and they were working on an atomic bomb,” Hildebrand said of the Germans. “The consequence of losing a nuclear race was the preoccupation of everyone who knew that a nuclear bomb might be possible.”
Outgrowths of chain reaction
The scientific staff of the Metallurgical Laboratory founded the Atomic Scientists of Chicago on Sept. 26, 1945—just weeks after the United States dropped the atomic bomb on Hiroshima and Nagasaki. The group published the first issue of the Bulletin of the Atomic Scientists of Chicago on Dec. 10, 1945. The Bulletin’s Doomsday Clock still stands as a symbol of humanity’s vulnerability to man-made catastrophe, with an agenda that expanded from nuclear weapons to include climate change and biological weapons.
Medical research gained unexpected benefits from the wartime research. In the early 1950s, the Atomic Energy Commission funded the Argonne Cancer Research Hospital, which became the Franklin McLean Institute, 5841 S. Ellis Ave., in 1973. The Argonne Hospital successfully pioneered the use of radiation in cancer treatment, with efforts later expanding to include radiological innovations in the diagnosis and treatment of other diseases.
Although the University of Chicago already was renowned in physics and chemistry before World War II, scientists who worked on the Manhattan Project helped those departments attain new research prominence following the war. Numerous UChicago scientists who were part of the war effort won Nobel Prizes for scholarly work in the postwar period, including Owen Chamberlain, Eugene P. Wigner, and Glenn Seaborg. Fermi, one of the most important scientists of the 20th century, became an inspiring teacher at UChicago after the war before dying of stomach cancer in 1954. The National Accelerator Laboratory in Batavia was renamed in Fermi’s honor in 1974, and became known as Fermilab, the site of numerous fundamental advances in particle physics.
UChicago builds for the future
Today, the William Eckhart Research Center is rising from a construction site directly across the street from where Fermi and his associates achieved the first controlled, self-sustaining nuclear chain reaction. The Eckhart Center will occupy the site of the former Research Institutes building, where Fermi and many other Manhattan Project veterans did transformative research.
UChicago scientists formally honored the Research Institutes’ legacy in June 2011, when they publicly revealed the contents of the time capsule that Fermi had sealed within the Research Institutes building cornerstone nearly 62 years earlier. In retrospect the cornerstone’s contents, which included booklets on the institutes and a sketch of their building, barely hinted at the accomplishments that would follow. That inspiring legacy survives to this day, said Robert Fefferman, dean of the University’s Physical Sciences Division.
“This is not just something about the distant past,” Fefferman, remarked at the cornerstone unveiling ceremony. “This is something that continues, and we’re extremely proud of the grand tradition of science here.”