As seen through the blast maps, there was a significant amount of destruction
from the explosions, approximately 3 miles in Hiroshima and in Nagasaki.
The immense destruction and burning from the explosions of the bombs were
the initial impact on the land; however, there was a secondary form of destruction that wreaked havoc on the area; radiation. Little Boy and Fat Man were constructed during the Manhattan Project with the plan of an atomic bomb even though they both used different design types. First was the Fat Man, which is an implosion triggered bomb. The basic process is that the explosives are fired which causes a shock wave. The shock wave compresses the plutonium and uranium core causing a fission reaction. From here, the bomb exploded releasing the energy, fire and radiation to the earth (Freudenrich).
from the explosions, approximately 3 miles in Hiroshima and in Nagasaki.
The immense destruction and burning from the explosions of the bombs were
the initial impact on the land; however, there was a secondary form of destruction that wreaked havoc on the area; radiation. Little Boy and Fat Man were constructed during the Manhattan Project with the plan of an atomic bomb even though they both used different design types. First was the Fat Man, which is an implosion triggered bomb. The basic process is that the explosives are fired which causes a shock wave. The shock wave compresses the plutonium and uranium core causing a fission reaction. From here, the bomb exploded releasing the energy, fire and radiation to the earth (Freudenrich).
Secondly was the Little Boy. This design process is different because it
is gun-triggered fission bomb. The detonation process of the Little Boy goes as
follows: the explosion fires causing the small Uranium bullet fire through the
barrel and strikes the Uranium sphere causing fission. From here, the bomb
explodes just like the Fat Boy (Freudenrich). This is how the explosions
occurred and how radiation entered the atmosphere.
The assumed flow of radiation would be similar to the blast radius from the bombs. The amount of radiation near the hypocenter of the blast should be where it is highest. The amount of radiation would then be less and less as you moved further along the radius of the blast. However, this is not what occurred in Hiroshima and Nagasaki. After the explosion, there were massive fires, dust and debris, and a handful of chemicals in the air. As these all mixed after the blasts, a cumulonimbus cloud was created. The cloud was moving east-southeasterly at a speed of 3 m/s (or approximately 7 mph) (Yoshida). The cloud began to rain, but it wasn't normal rain.The water was mixed with the dust and debris and was called “black rain”. However, the rain also contained amounts of 239+240Pu(plutonium and uranium) from the blast. While the concentration of plutonium varied, it still contained radiation. With the rain and the wind moving the cloud east southeast, the radiation began to spread away from the hypocenter and began to cause more damage than expected. According to a study in the Journal of Radioanalytical and Nuclear Chemistry, a group of scientists tested the amount of 239+240 Pu in soil levels in Nagasaki and the surrounding cities on the island. Their findings are shown in the Radiation Levels map shown above. The highest level of plutonium and radiation was found in the Nishiyama region, about 3 km east of the hypocenter. Likewise, there were amounts of plutonium found over 100 km away from the hypocenter in the Ohita region (Yoshida). The map also shows how there are amounts of plutonium surrounding the entire radius of the blast, but also similar amounts found moving east of Nagasaki. The data collected by the scientists is accurately depicted by the weather from the day and how the black rain and wind spread the radiation. It also explains how the entire region of Nagasaki was affected by the radiation even though the blast destruction only spanned a few miles (Destructive Effects: Energy and Radioactivity).