How Deep Does a Bunker Have To Be To Survive A Nuke?

When a ballistic missile alert was mistakenly sent out on January 13, 2018, in Hawaii, it caused residents to panic! The thought of being under a nuclear attack in the 21st century is terrible and terrifying. People with understandably seek shelter in an underground bunker, if there’s one near.

But how deep does a bunker have to be to survive a nuke? The bunker has to be more than 1,000 feet buried beneath the earth. Of course, the depth itself isn’t the only consideration since materials, location, and construction matter.

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Read on and find out the reason for the 1,000-feet answer and the other factors for consideration. I will as well discuss the most important features when building a nuclear bunker. 

The Power Of An EPW

Nuclear weapons can be deployed in a variety of ways, with each method characterized by specific effectiveness. The simplest method is by dropping the nuke from an aircraft, such as tactical fighter bombers and strategic bombers.

Little Boy and Fat Man are said to be dropped from an aircraft over Hiroshima and Nagasaki, respectively.

But there are other ways, too, such as mounted on missiles and multiple independently targetable reentry vehicles (MIRVs). Perhaps the most destructive of these methods is via earth-penetrating weapons (EPW) system where fallout shelters are concerned.

EPWs smash the earth at high speeds, penetrate the ground and then explode, resulting in extensive damage to underground structures.

While the earth slows it down so it cannot penetrate deeply, most of its energy upon explosion will be transmitted to the ground. In turn, the explosion sends a powerful seismic shock wave that causes significant damage to an underground bunker.

But even an EPW has limited effectiveness partly because, again, the earth acts as a natural barrier. Even the 1.2 megatons B83 warhead, currently considered as the highest yield weapon in the U.S., has its limits!

While it can crush 1,000-foot deep underground bunker, it cannot penetrate bunkers at deeper depths. 

The General Features Of An Effective Bunker

But it isn’t just the depth of an underground bunker that matters during a nuclear attack! If you’re planning to build one or look for one, you should consider these aspects.

  • The doors and walls should have equal strength to survive the blast, whether from an EPW or other nuclear weapons. Steel blast doors used in nuclear power plants are considered the best. These are usually made of thick concrete with a steel envelope for reinforcement.

  • The bunker should have enough ventilation, preferably manually operated ventilators since gas and electricity supply can be unreliable in wartime. The Kearny Air Pump comes highly recommended. Many luxury bunkers also have an air filtration system capable of removing biological, nuclear, and chemical contaminants. 

Of course, an ideal bunker should have food and water provisions, medical supplies, and other emergency items. After all, it doesn’t make sense to survive a nuclear blast and die of hunger!

Conclusion

While the possibility of a nuclear strike against the United States is low, you may want to consider your shelter options! You can read resources like Emergency Air: For Shelter-in-Place Preppers and Home-Built Bunkers for starters.