About 1200 tons of uranium ores stored in Staten Island adjacent to Manhattan in New York City were developed and manufactured for Atomic Bombs. The target of Uranium 235 contained only 0.7% of Uranium 238. A large amount of Plutonium 239 could be purified from inside the nuclear reactor with Uranium 238 absorbing the neutrons. Even though Plutonium 240 contained in Plutonium 239 spontaneously fission and releases neutrons. An atomic bomb device should be developed in which plutonium 239 could caused a nuclear fission chain reaction.
The Plutonium type of Nagasaki atomic bomb generated neutrons from the center and were absorbed into the Plutonium 239. Furthermore, Uranium 238 mainly surrounded them, and strong bomb were scattered spherically from the outside. Plutonium 239 were strongly imploded and chain reactions of nuclear fission occurred in the central part and exploded with super- destructive energy. Implosion of Plutonium 239 were extremely difficult. It succeeded for the first time in history by the Trinity experiment on July 16, 1944.
