Vision and reality : The EBR - II story

spring 1944. Work at Los Alamos, Oak Ridge, and Hanford to design, build, and provide fissionable material for the first atomic bombs was shifting into high gear. In stark contrast, initial bomb project studies on the nuclear chain reaction and plutonium were winding down at the Chicago Metallurgical Laboratory, Argonne National Laboratory’s wartime predecessor. Even as others zeroed in on the remaining wartime technical challenges, Chicago scientists turned their attention to the postwar possibilities for peaceful uses of nuclear energy. As part of this transition, on the morning of April 26, 1944, Enrico Fermi, Leo Szilard, Eugene Wigner, Alvin Weinberg and others gathered to discuss the possibilities for using nuclear fission to heat and light cities. The scarcity of fissile material was on everyone’s mind—it was agonizingly unclear at that time whether there was sufficient fissile material for usable wartime bombs. Fermi and the others therefore cast around for ways to produce maximum civilian power with minimal resources. They hit upon a novel scheme: designing a civilian power reactor that produced more fissile material than it consumed. Their plan was to place uranium-238 (or some other fertile material) near the reactor’s core to capture the excess neutrons and thereby to breed new fissile fuel. They decided that such a device, which was later called a breeder reactor, would have to use fast neutrons—that is, neutrons would not be moderated as in most of the weapons materials reactors then in existence. According to their calculations, with fast fission, enough neutrons would be created in the course of power production to hit the Instead of becoming a stepping stone to EBR-III, EBR-II followed an unexpected path in the 30 years after construction. Vision and reality: The EBR-II story