The National Emergency Alarm Repeater (NEAR) program was developed in the United States in 1956 during the Cold War to supplement the existing siren warning systems and radio broadcasts in the event of a nuclear attack. These buildings were placarded with the orange-yellow and black trefoil sign designed by United States Army Corps of Engineers director of administrative logistics support function Robert W. Plans were made, however, to use existing buildings with sturdy below-ground-level basements as makeshift fallout shelters.

1963ĭuring the Cold War, many countries built fallout shelters for high-ranking government officials and crucial military facilities, such as Project Greek Island and the Cheyenne Mountain nuclear bunker in the United States and Canada's Emergency Government Headquarters. Department of Defense, Office of Civil Defense. History North America Fallout shelter water storage can: a 66 liters ( 17 + 1⁄ 2 U.S. gal) barrel issued by the U.S.

A fallout shelter is designed to allow its occupants to minimize exposure to harmful fallout until radioactivity has decayed to a safer level, over a few weeks or months. Much of this highly radioactive material falls to Earth, subjecting anything within the line of sight to radiation, becoming a significant hazard. The fallout emits alpha and beta particles, as well as gamma rays. When this material condenses in the rain, it forms dust and light sandy materials that resemble ground pumice. Many such shelters were constructed as civil defense measures during the Cold War.ĭuring a nuclear explosion, matter vaporized in the resulting fireball is exposed to neutrons from the explosion, absorbs them, and becomes radioactive.

A fallout shelter is an enclosed space specially designated to protect occupants from radioactive debris or fallout resulting from a nuclear explosion.

What does level do in fallout shelter