Nuclear+Fission+Project

**Nuclear Fission**

//**Background:**// Nuclear fission is the splitting of the nucleus of an atom into smaller, subatomic particles. This splitting of the atom produces free neutrons and photons. This process of fission, when used with heavy elements, can produce large amounts of energy. This energy can be used for nuclear power as well as very potent bombs and explosives.



An induced fission reaction. A slow-moving neutron is absorbed by a uranium-235 nucleus turning it briefly into a uranium-236 nucleus; this in turn splits into fast-moving lighter elements (fission products) and releases three free neutrons.

//**History:**// Around 1911, New Zealander Lord Ernest Rutherford modeled an atom as the smallest particle in matter that could not be divided. Danish Physist Neils Bore, improved the model of the atom and depicted it as a mini solar system where the nucleus was constantly orbited by electrons and protons. It was concluded by scientists Marie Curie and Peirre Curie that the atom had a nucleus of protons and neutrons orbited by electrons. Albert Einstein confirmed that was the correct description of an atom. In 1917, Nuclear transmutation was accomplished by Ernest rutherford where he was able to make water by combining atoms of hydrogen and oxygen together

[|Educational video on atoms]
In 1934, Enrico Fermi believed that he had synthesized elements that had a higher atomic number than uranium's 92, the highest known at the time. Because of the lack of knowledge of chemistry at that time, he was not able to prove this by separating the products of uranium. His discoveries, though, did not go unnoticed. Lise Meitner put a team together to investigate Fermi's ideas. With the help of Fritz Strassman and Otto Hahn, she began to investigate neutron induced uranium decay. In 1938, Meitner fled to Sweden to escape the Nazis (she was of Jewish descent). This did not stop her research, though. By way of sending letters, the team ultimately made an important discovery; uranium nuclei had been broken apart into elemental fragments (one of which was barium).  This explained Fermi's process, and Meitner proceeded to call this discovery “Nuclear Fission”.



**//Science//:**In Nuclear Fission, a very heavy nucleus splits into more stable nuclei of smaller masses. This releases great amounts of energy. This process can occur either spontaneuously or when nuclei are bombarded by particles. For example, uranium-235 can be bombarded with neutrons and pick up one of these neutrons, making it very unstable, ultimately resulting in enormous amounts of energy.  Nuclear Fission can occur in chain reactions, in which the neutrons released from fission produce more fission in at least one nucleus. This process can be controlled or uncontrolled. When it is uncontrolled, it is used for weapons. The only way the process can be controlled is if only one neutron is allowed to strike the nucleus, for every 2-3  neutrons released. When designing nuclear weapons, scientists have to consider the spontaneous nuclear fission rate. This is the amount of time it will take for an atom to fission and ultimately for the bomb to explode, without any external factors (such as scientists controlling the fission). When neutrons are released from the atom, they travel at a speed of 10 million meters per second. The total time for this process to occur and the weapon to explode is about a microsecond. During the Manhattan project, this amount of time was referred to as a “shake” by the scientists, because it was seemingly as quick as a shake of a lambs tail.

<span style="color: #0000ee; font-family: 'Times New Roman',Times,serif; font-size: 130%;">[|Nuclear Fission Process]

<span style="font-family: 'Times New Roman',Times,serif; font-size: 130%;">//**Manhattan Project:**// The Manhattan project was a secret military mission in 1932 in which the U.S. Attempted to build their first nuclear weapon. This project was triggered out of fear that Germany may also be working on a similar project. The development of the bomb did not start until 1942. U.S. physicist Robert Oppenheimer and General Leslie R. Groves were the directors of the project. They recruited many brilliant European men to work on the project, such as Albert Einstein (Even though he had stated for scientists to stay away from military matters), Enrico Fermi, and Leo Szilard. They also recruited a large number of brilliant U.S. scientists and engineers. Three main areas of study were also established in Tennessee, New Mexico, and Washington. Each served a different part in the project. The Tennessee lab stored uranium 235, the Washington lab stored plutonium, and the Los Alamos, New Mexico lab was where the nuclear weapons would be assembled. This became the most famous lab because it is where the real work was done. This project ultimately produced four nuclear weapons. Two of these weapons were used during World War II on Hiroshima and Nagasaki. They were named Little Boy and Fat Man. This project officially ended in 1946 when it joined the organization called the Atomic Energy Commission.



<span style="color: #0000ee; font-family: 'Times New Roman',Times,serif; font-size: 130%;">[|Manhattan Project Video] <span style="color: #0000ee; font-family: 'Times New Roman',Times,serif; font-size: 130%;">[|Manhattan Project Nuclear Tests]

<span style="font-family: 'Times New Roman',Times,serif; font-size: 140%;">**//Hiroshima and Nagasaki://**

<span style="display: block; font-family: 'Times New Roman',Times,serif; font-size: 130%; text-decoration: inherit;">On August 6, 1945, the United States dropped their first atomic weapon on Hiroshima, Japan. This atomic bomb crushed the city and killed thousands of civilians. Only three days later, the U.S. dropped another devastating bomb on Nagasaki. Hiroshima was the first bomb to drop. It was carried by the plane Enola Gray and contained Uranium- 235. It was named "Little Boy". William S. Parsons was responsible for activating the bomb. He was an important part of the Manhattan Project. This activation took him 15 minutes. The bomb was dropped 1,900 feet above the city and caused mass destruction in the surrounding area. Co- pilot of the flight, <span style="display: inline !important; text-decoration: inherit;">Captain Robert Lewis stated, "Where we had seen a clear city two minutes before, we could no longer see the city. We could see smoke and fires creeping up the sides of the mountains." The second bomb, "Fat Man" was dropped three days later over Nagasaki, and was released at 1,650 feet. The original target for the U.S. was Kokura, but the city was not visible, so the bomb could not be dropped here. These first two nuclear weapons ever used by the U.S. caused an immense amount of damaged and changed World War II. Without the development of the Manhattan Project and the work of Enrico Fermi and Lise Meitner, this turning point in the war would have never been possible. [|Hiroshima and Nagasaki Video]

<span style="font-family: 'Times New Roman',Times,serif; font-size: 130%;"> //**Modern Day:**// In today's world, nuclear fission is widely used. It is still used for creating nuclear weapons, even as other advances have come, such as the hydrogen bomb. Any country that wants saf  ety and security usually must have the threat of nuclear warfare, so there is always a push for new ways to make nuclear weapons and the use of nuclear fission. Des truction is not the only use, though. Today, nuclear fissio n is used in power plant  s, creating energy. The power plants use energy as heat from nuclear reactors to produce electrical energy. The power plants have five main components: shielding, fuel, control rods, a moderator, and a coolant. Uranium- 235 is typically used for this creation of electrical energy.

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