Nuclear weapon effects
PSI (Pounds per Square Inch)
The unit used to measure blast overpressure from a nuclear detonation.
1 PSI is a small overpressure that breaks windows. 5 PSI collapses most residential buildings and is the standard measurement for nuclear-blast damage zones. 20 PSI destroys reinforced concrete. By comparison, normal atmospheric pressure at sea level is about 14.7 PSI.