Los Alamos historian gives overview of Manhattan Project to Aiken group
Aug. 18—The people attending the Citizens for Nuclear Technology Awareness Up and Atom Breakfast on Wednesday morning got a history lesson on the World War II project that led to the creation of the Savannah River Site.
Alan Carr, program manager and senior historian at Los Alamos National Laboratory, presented an overview of the Manhattan Project at Newberry Hall.
The Manhattan Project was the name of the World War II operation that led to the creation and use of the first nuclear weapons in 1945. The project spent around $2 billion and employed over 130,000 people .
Carr said the results of the Manhattan Project were two types of nuclear weapon designs: a simple, gun-fusion design and a more complicated implosion style nuclear weapon. He said there were three main sites for the development of nuclear weapons: Los Alamos, New Mexico; Oak Ridge, Tennessee; and Hanford, Washington.
Los Alamos is where the designs of the bombs where made, Carr continued.
He said one way the designs differ is the type of fissionable material they use.
The simple type of design uses uranium 235 as its fissionable material.
Uranium 235 is one of three main types of uranium that naturally occur on the earth. The others are uranium 238 and uranium 234. Of these, uranium 238 is about 99.3% of the uranium found on Earth and uranium 235 around 0.7% with uranium 234 occurring in trace amounts.
Uranium 235 is the only one of the three types that is fissionable, and it must be separated from the nearly chemically identical uranium 238 and its proportion increased or enriched.
Carr said uranium enrichment was done in Oak Ridge, and that Little Boy, the first nuclear weapon dropped on Japan, was this type of nuclear weapon.
The more complicated implosion style weapon uses plutonium 239.
Plutonium occurs in very, very small amounts in nature but plutonium 239 is made from uranium 238. Basically, the uranium 238 captures a neutron and then emits a proton and an anti-neutrino over the next two days to become plutonium 239.
Carr said the Hanford Site , complete with several nuclear reactors, was established to generate the plutonium for this type of weapon. He added Fat Man, the second bomb dropped on Japan, was this type of bomb. Carr said DuPont was selected to manage and operate the Hanford Site.
After the Japanese surrendered, a rivalry developed between two of the victors in the war, the United States and the Soviet Union. The Soviets were able to detonate a nuclear weapon based on the implosion style weapon used in World War II in 1949 thanks to their capture of some of the German scientists who worked on that country's nuclear program and their spy ring inside the Manhattan Project.
The Soviet detonation inspired President Harry Truman to order the development of more nuclear weapons and the Savannah River Site was created to supply plutonium for those new nuclear weapons. Once again, DuPont was selected as the manager and operate of the site.
