Little-Acorn
12-05-2011, 07:39 PM
Sorry about the screwball date, but I just found out about this.
On Dec. 2, 1942, Enrico Fermi created the first manmade self-sustaining nuclear chain reaction.
He stacked up a lot of graphite blocks, interspersed with pellets of uranium and rods coated with cadmium metal. For want of a better name, he called it a "pile". The name "nuclear reactor" didn't come into use for many years. It had no radiation shielding, and no cooling system. It was built under the stands of an abandoned football field in Chicago. When they began to pull the cadmium-caoted rods out, radioactivity increased, and soon they calculated that they had a self-sustaining chain reaction going. The rods were quickly pushed back in.
Had the reaction gotten away from them, they probably wouldn't have gotten a Hiroshima-type bang. But they would have probably created the world's first "neutron bomb", and possibly a "China Syndrome" style meltdown, making much of central Chicago uninhabitable for the next thousand years or so.
Fortunately, they didn't.
One of the reasons for wanting to create such a self-sustaining chain reaction of uranium, is that other scientists had determined they could create a man-made element Plutonium if they had enough neutrons shooting around. They had created it, one atom at a time, in a magnetic cyclotron in Berkeley, CA, but it might be possible to mass-produce it if a self-sustaining uranium reaction could be created, producing huge amounts of neutrons. Once Fermi proved it was possible, the U.S. Government bought large tracts of land in Hanford, Washington in 1942 and 1943 to build several large uranium "piles". The Manhattan Project was born, and the rest is history.
Scientists weren't sure whether uranium or plutonium would make a better bomb. Uranium was more stable, but plutonium easier to produce once Fermi's process proved workable. They wound up building two plutonium bombs and one uranium bomb. One plutonium bomb was detonated at the Trinity test site in July 1945. Three weeks later the uranium bomb was dropped on Hiroshima, and three days after that the other plutonium bomb on Nagasaki. They also built a fourth bomb, but never produced enough nuclear material for it before the war ended.
On Dec. 2, 1942, Enrico Fermi created the first manmade self-sustaining nuclear chain reaction.
He stacked up a lot of graphite blocks, interspersed with pellets of uranium and rods coated with cadmium metal. For want of a better name, he called it a "pile". The name "nuclear reactor" didn't come into use for many years. It had no radiation shielding, and no cooling system. It was built under the stands of an abandoned football field in Chicago. When they began to pull the cadmium-caoted rods out, radioactivity increased, and soon they calculated that they had a self-sustaining chain reaction going. The rods were quickly pushed back in.
Had the reaction gotten away from them, they probably wouldn't have gotten a Hiroshima-type bang. But they would have probably created the world's first "neutron bomb", and possibly a "China Syndrome" style meltdown, making much of central Chicago uninhabitable for the next thousand years or so.
Fortunately, they didn't.
One of the reasons for wanting to create such a self-sustaining chain reaction of uranium, is that other scientists had determined they could create a man-made element Plutonium if they had enough neutrons shooting around. They had created it, one atom at a time, in a magnetic cyclotron in Berkeley, CA, but it might be possible to mass-produce it if a self-sustaining uranium reaction could be created, producing huge amounts of neutrons. Once Fermi proved it was possible, the U.S. Government bought large tracts of land in Hanford, Washington in 1942 and 1943 to build several large uranium "piles". The Manhattan Project was born, and the rest is history.
Scientists weren't sure whether uranium or plutonium would make a better bomb. Uranium was more stable, but plutonium easier to produce once Fermi's process proved workable. They wound up building two plutonium bombs and one uranium bomb. One plutonium bomb was detonated at the Trinity test site in July 1945. Three weeks later the uranium bomb was dropped on Hiroshima, and three days after that the other plutonium bomb on Nagasaki. They also built a fourth bomb, but never produced enough nuclear material for it before the war ended.