Bunker Shielding

Nuclear Fallout

A basic fallout shelter consists of shields that reduce gamma ray exposure by a factor of 1000. The required shielding can be accomplished with 10 times the amount of any quantity of material capable of cutting gamma ray effects in half. Shields that reduce gamma ray intensity by 50% (1/2) include

  • 1 cm (0.4 inch) of lead
  • 6 cm (2.4 inches) of concrete
  • 9 cm (3.6 inches) of packed dirt or
  • 150 m (500 ft) of air.

When multiple thicknesses are built, the shielding multiplies. Thus, a practical fallout shield is ten halving-thicknesses reducing the radiation as seen in the chart below.

Layer Radation
No Shielding 1000
1 500
2 250
3 125
4 62.5
5 31.25
7 15.625
7 7.8125
8 3.90625
9 1.953125
10 0.9765625

fallout shelterAs seen in the photo a structure can be inside a structure to increase shielding. You can also fill the ceiling with items such as brick, sand, etc if the ceiling/floor joists will support the extra weight. If the joists will not allow for extra material then think about adding the material only once you are using the shelter to reduce the risk of collapse.

Electromagnetic Pulse (EMP)

What Is EMP and How Is It Created?

The most important mechanism for Electromagnetic Pulse (EMP) production from a nuclear detonation is the ionization of air molecules by gamma rays generated from the explosion. These gamma rays ionize the air molecules by interacting with the air molecules to produce positive ions and recoil electrons called Compton electrons. This pulse of energy, which produces a powerful electromagnetic field, particularly within the vicinity of the weapon burst, is called an electromagnetic pulse. EMP can also be produced from non-nuclear sources, such as electromagnetic bombs, or E-bombs.

High-altitude nuclear detonations and electromagnetic bombs can generate EMP that has the potential to damage or destroy electronic devices over widespread areas. Electric power systems would also be at risk from surges produced by such weapons. However, the EMP from a kiloton-range surface nuclear explosion would not be expected to produce serious damage outside the radius of severe destruction from blast.

A 1.4 Megaton bomb launched about 250 miles above Kansas would destroy most of the electronics that were not protected in the entire Continental United States. During the brief return to atmospheric testing in 1962, a 1.4 megaton nuclear weapon was detonated over Johnston Island at an altitude of about 250 miles. The effects of EMP were observed in Hawaii, 800 miles east of the detonation. Streetlights and fuses failed on Oahu and telephone service was disrupted on the Island of Kauai.

How Do I Shield My Electronics

Shields are made of a continuous piece of metal such as steel or copper. A metal enclosure generally does not fully shield the interior because of the small holes that are likely to exist. Commonly, only a fraction of a millimeter of a metal is needed to supply adequate protection. This shield must completely surround the item to be hardened.

For our shield we have modified two large over the counter tool box to hold all of our electronics. To eliminate holes the box has been welded shut except one small section on top that has been designed to allow a metal plate to be screwed on after the electronics have been insert. This plate is made of a soft metal that will when screwed tight will seal the gaps. The screws also have washer to perform the same task. This will then be covered in foil and grounded.

We have also modified our generator so the electronic panel can removed and inserted into the one of the tool boxes.