A Slow Beginning
The project began slowly. Franklin D. Roosevelt designated Lyman Briggs to head a committee to investigate the issues raised in the Einstein-Szilárd letter. A meeting attended by a few scientist of the time was held in October 1939 resulting in a report to the president that the element uranium had capabilities to produce bombs that were liken one prior. Briggs urged the National Defense Research Committee to allocate $167,000 to the research of uranium as well as the recently discovered element, plutonium.1
Japanese Attack
Attack on Pearl Harbor
On the 7th of December 1941, Japan launched a surprise attack on Pearl Harbor, Hawaii. The isolationist US were forced into the war by this action; declaring war against the Japanese and Nazis the day after the attack. In January 1942, the go ahead for full scale development of nuclear weapons was given by the president. By this time it was obvious that large factories would eventually have to be built. Because the work was now being done in secrecy, and considerable construction was foreseen, the Manhattan Engineer District of the U.S. Army Corps of Engineers lead by Leslie R. Groves was created in August 1942 to oversee the entire atomic bomb program. This is where the name of The Manhattan Project originates. Soon after taking command of the operation, Groves assigned Robert Oppenheimer as director of the development and sciences of the project. Oppenheimer was a highly capable and knowledgeable man.
Locations
Secrecy of the project was highly important. The public and the enemy were not to know anything of the Manhattan Project. Protecting the secrecy of the project was one of the most complex security and intelligence operations during the war. Therefore, it was important that the locations of where the experimentation took place was optimal to guarantee security. Also it was important to guarantee that if an accident does happen, the fallout did not affect major populations.
The project took place in four main locations: Oak Ridge, Tennessee; Los Alamos, New Mexico; Hanford, Washington and the most intriguing, under an unused football stadium of the University of Chicago.
Each location had its own tasks, Oak Ridge was allocated the task of separating different isotopes of uranium. Hanford, Washington was a place where a fissionable plutonium isotope was synthesized from uranium. The Chicago location was used to test set up the world's first nuclear reactor known as Chicago Pile-1, this was used to conduct nuclear fission experiments. Finally, Los Alamos was chosen by Oppenheimer himself to be the headquarters of the operation.
At all locations many sacrifices were made, thousands of people were relocated, huge construction efforts happened in Hanford and Oak Ridge to accomodated the scientists and workers of the project. To ensure secrecy, private telephones, radios and most forms of communication was banned and children did not use their full names in schools and people were encouraged to use pseudonyms when outside of the lab.
The project took place in four main locations: Oak Ridge, Tennessee; Los Alamos, New Mexico; Hanford, Washington and the most intriguing, under an unused football stadium of the University of Chicago.
Each location had its own tasks, Oak Ridge was allocated the task of separating different isotopes of uranium. Hanford, Washington was a place where a fissionable plutonium isotope was synthesized from uranium. The Chicago location was used to test set up the world's first nuclear reactor known as Chicago Pile-1, this was used to conduct nuclear fission experiments. Finally, Los Alamos was chosen by Oppenheimer himself to be the headquarters of the operation.
At all locations many sacrifices were made, thousands of people were relocated, huge construction efforts happened in Hanford and Oak Ridge to accomodated the scientists and workers of the project. To ensure secrecy, private telephones, radios and most forms of communication was banned and children did not use their full names in schools and people were encouraged to use pseudonyms when outside of the lab.
Fuel
The most important element of the project was uranium. It was discovered that uranium could undergo nuclear fission and was suitable for a nuclear weapon. The required isotope was uranium-235, however the most common isotope of uranium was uranium-238. However, the issue was that U238 was not suitable for the project. The issue with acquiring the required U235 isotope was that it only made up around 0.7% of natural uranium. Since both the isotopes had similar chemical properties, the U235 isotope had to be physically separated from the more abundant U238.2 Many ways of obtaining the required isotope were tested and eventually a method was devised to separate the isotopes known as gaseous diffusion. The Oak Ridge facility was designated the task of separating the two isotopes.
A recently discovered element, plutonium was soon discovered to also be able to support a nuclear chain reaction. It was found that the plutonium 239 isotope was suitable. However, little was known about the recently discovered plutonium. Much research was done and in spring 1942 scientist Ernest Lawrence discovered that P239 could be synthesized from U238. This was a highly beneficial discovery, the plutonium isotope was able to be relatively more easily obtained than the U235 isotope. The Hanford, Washington site was given the task to obtain the plutonium fuel.
Now that a way to obtain the fuel was discovered, the next step was obtaining enough to sustain a reaction. It was discovered that uranium required 52kg of highly pure U235 isotope to sustain a reaction,3 plutonium was found to require around 10kg.4 The amount that an radioactive element needs to sustain a reaction is known as its critical mass.5 The required amounts of radioactive material was very difficult to obtain with the methods and technologies of the time, much work had to be put into producing the elements and only small amounts were obtained. The obtaining of the required kilograms of the scarce substances proved to be a huge challenge.
Now that suitable fuels were found, testing and design of the weapon was the next step.
A recently discovered element, plutonium was soon discovered to also be able to support a nuclear chain reaction. It was found that the plutonium 239 isotope was suitable. However, little was known about the recently discovered plutonium. Much research was done and in spring 1942 scientist Ernest Lawrence discovered that P239 could be synthesized from U238. This was a highly beneficial discovery, the plutonium isotope was able to be relatively more easily obtained than the U235 isotope. The Hanford, Washington site was given the task to obtain the plutonium fuel.
Now that a way to obtain the fuel was discovered, the next step was obtaining enough to sustain a reaction. It was discovered that uranium required 52kg of highly pure U235 isotope to sustain a reaction,3 plutonium was found to require around 10kg.4 The amount that an radioactive element needs to sustain a reaction is known as its critical mass.5 The required amounts of radioactive material was very difficult to obtain with the methods and technologies of the time, much work had to be put into producing the elements and only small amounts were obtained. The obtaining of the required kilograms of the scarce substances proved to be a huge challenge.
Now that suitable fuels were found, testing and design of the weapon was the next step.
Personnel
The project started humbly, with only a few scientists and personnel. As the project gradually escalated, the number of people involved with the project also increased. Oppenheimer spent three months of 1943 scouring the country for the best scientist of the time.6 At the height of the project, in June 1944, there were around 130,000 people involved around the sites. A large majority, 84,500, were construction workers; 40,500 people were plant operators and 1,800 were military personnel.6 Many skilled scientist of the time such as Robert Oppenheimer, Leo Szilard, Niels Bohr, Enrico Fermi and Edward Teller all worked at the project. Also, many young scientist of the time were attracted to the project. Like most industrial efforts during the war, women played a huge role during the project; working on all the sites of the project.
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1. Hewlett, Richard G.; Anderson, Oscar E. The New World, 1939–1946 Pg 40-412.
2. http://en.wikipedia.org/wiki/Enriched_uranium
3. http://en.wikipedia.org/wiki/Uranium-235
4. http://en.wikipedia.org/wiki/Plutonium-239
5. http://en.wikipedia.org/wiki/Critical_mass
6. http://www.atomicarchive.com/History/mp/p4s27.shtml
2. http://en.wikipedia.org/wiki/Enriched_uranium
3. http://en.wikipedia.org/wiki/Uranium-235
4. http://en.wikipedia.org/wiki/Plutonium-239
5. http://en.wikipedia.org/wiki/Critical_mass
6. http://www.atomicarchive.com/History/mp/p4s27.shtml
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