Breeder Reactor Produces Plutonium from Uranium

In the fledgling days of nuclear science, uranium was a scarce commodity. In fact, when the EBR-I was built, all U.S. uranium was under the authority of the military. Enrico Fermi came up with the concept of a “breeder” reactor which would produce more fuel than it used. The concept behind a breeder reactor involves Uranium 235, a radioactive material, releasing neutrons, which then collide with uranium nuclei and splits them, a process that releases both heat and more neutrons. These reactions increase quickly over time, with a slowing of the chain reactions accomplished by the insertion of control rods that slow down the rate of fission by stopping the neutrons. The production of plutonium was accomplished by using Uranium 238 “bricks” around the reactor which were converted to Plutonium 239 when bombarded by neutrons. In 1953, samples of the U-238 bricks were analyzed at Argonne’s Chicago laboratory and confirmed that fissionable plutonium had been produced from non-fissionable uranium thereby breeding fuel in the process of burning fuel.