In a shelter with a PF of 200, you would receive 1/200 th of the dose you would have received in the open. How well a shelter protects against fallout is measured as Protective Factor (PF). This is why many fallout shelters are built in basements or abandoned mines: the layers of dirt provide natural protection against fallout. The more material you have between you and the fallout, the more protection you will have.

What Makes a Good Fallout Shelter?įallout shelters need to be made from thick layers of dense material. It lets you map a nuclear bomb’s blast area and fallout distance and even lets you change wind direction to see how far fallout would blow. By getting into a shelter quickly, you can avoid the lethal fallout levels immediately after the blast. Instead, the purpose of a fallout shelter is to protect you from the radioactive particles falling from the sky. It is not meant to help you survive the destruction from a nuclear bomb.Įven if you had enough warning to get to a bomb shelter, experts generally agree that a nuclear bomb would vaporize everything within 0.3 miles of Ground Zero. What Are Fallout Shelters?Ĭontrary to what some people think, a fallout shelter is not the same as a bomb shelter. While you hopefully never will need this information, it can’t hurt to know where fallout shelters are located nearby and what to do if a nuclear alert goes off. This “delayed fallout” could cause radioactive particles to fall all over the earth – which is why knowing where a fallout shelter is essential, even if you don’t live near a potential target. Wind and rain can cause fallout to spread far away from the blast site. You’d need to immediately get in a fallout shelter to avoid getting poisoned. The radioactive debris then falls back to the earth, contaminating everything it touches. The fireball would shoot miles into the atmosphere – pulling dirt and debris with it. If a nuclear bomb were to hit, the blast would create a massive fireball which would vaporize everything nearby.

US army fallout shelter plans