Chain reactions, nuclear first self-sustaining

The Manhattan Project at the University of Chicago Laboratoi"y, headed by Enrico Fermi (Italian-American), creates the first self-sustaining nuclear chain reaction. Natural gas liquified for first time in Cleveland, Ohio. 

The very first nuclear reactor built, where the main objective was to perform condensed matter research, was the High Flux Beam Reactor (HFBR) at Brookhaven National Laboratory, Upton, NY. The first self-sustaining chain reaction at the HFBR took place on Halloween, 1965. For over 30 years, the HFBR was one of the premier beam reactors in the world, matched only by the ILL reactor in Grenoble, France. These reactor-based sources have been a continuous and reliable source of thermal neutrons for research in a wide range of different scientific fields from physics, chemistry, materials science, and biology to engineering and isotope emichment. The instrumentation that is in place at these sources has seen steady improvement from the days when Nobel laureates, Brockhouse and Shull, performed their pioneering work at these facilities. 

Compacted UO2 was used in the assembly of the first nuclear exponential lattice in July 1941. The first self-sustaining controlled nuclear chain reaction was achieved in the CP-1 uranium-graphite reactor on December 2, 1942, using 32,652 kg (36 tons) of uranium oxide (both UO2 and UsOs), as well as uranium metal. 

Scientists led by Enrico Fermi achieve the first self-sustained nuclear chain reaction in Chicago. 

June The U.S. War Department tasks the Army Corps of Engineers to establish the Manhattan Engineering District (MED), a secret effort to develop a nuclear weapon. MED wih become more popularly known as the Manhattan Project. 2 December The first self-sustaining chain fission reaction takes place in a nuclear pile at the University of Chicago. 

Shortly after Japan s December 7,1941 attack on Pearl Harbor, the U.S. became more driven to expedite its timetable for developing the first fission weapon because of fear that the U.S. lagged behind Nazi Germany in efforts to create the first atomic bomb. On December 2, 1942 at 3 49 p.m., Enrico Fermi and Samuel K. Allison achieved the world s first controlled, self-sustained nuclear chain reaction in an experimental reactor using natural uranium and graphite. 

Because the isotope uranium-235 is fissionable, meaning that it produces free neutrons that cause other atoms to split, it generates enough free neutrons to make it unstable. When the unstable U-235 reaches a critical mass of a few pounds, it produces a self-sustaining fission chain reaction that results in a rapid explosion with tremendous energy and becomes a nuclear (atomic) bomb. The first nuclear bombs were made of uranium and plutonium. Today, both of these fuels are used in reactors to produce electrical power. Moderators (control rods) in nuclear power reactors absorb some of the neutrons, which prevents the mass... 

On December 2, 1942, the first artificial self-sustaining nuclear fission chain reaction was achieved in an abandoned squash court at the University of Chicago. This accomplishment led to the development of the first atomic bomb, at Los Alamos National Laboratory in New Mexico in July 1945 (T FIGURE 21.17). In August 1945 the United States dropped atomic bombs on two Japanese cities, Hiroshima and Nagasaki. The nuclear age had arrived. 

History s first critical chain reaction was carried out in an atomic pile, which was literally a stack or pile of uranium-containing graphite blocks and blocks of pure graphite that served as a neutron moderator (see I Figure 10.11). The pile was constructed in a squash court beneath the stands of an athletic fieldhouse at the University of Chicago, and the experiments were carried out by a team of scientists led by Italian physicist Enrico Fermi. In December 1942, the team observed that nuclear reactions in the pile had become self-sustaining, or critical. The control rods, composed of strong neutron absorbers, were pushed into the pile to stop the reaction. 

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