An estimate of the dimensions in the damage caused by the sixteen kt and 21 kt atomic bombings of Hiroshima and Nagasaki. The substantial temperatures and radiation lead to gasoline to move outward radially in a thin, dense shell identified as "the hydrodynamic entrance". The entrance functions like a piston https://radiationzonemod08371.blogscribble.com/34756144/the-5-second-trick-for-zone-radiation-chernobyl