Dig this trench just under the ground's surface with an opening to the surface at the end of it. At the other end of the trench, dig a five-foot-long ventilation trench to help circulate air.

Step 2: Next, dig a five-foot-long entrance with steps or a slope down into the main area. Remember that any protection, however temporary, is better than none at all, and the more shielding, distance and time you can take advantage of, the better.Account icon An icon in the shape of a person's head and shoulders. Radioactive fallout poses the greatest threat to people during the first two weeks, by which time it has declined to about 1 percent of its initial radiation level. In time, you will be able to leave the fallout shelter. TIMEįallout radiation loses its intensity fairly rapidly. The heavier and denser the materials - thick walls, concrete, bricks, books and earth - between you and the fallout particles, the better. Flat roofs collect fallout particles so the top floor is not a good choice, nor is a floor adjacent to a neighboring flat roof. A floor near the middle of a high-rise may be better, depending on what is nearby at that level on which significant fallout particles would collect. An underground area such as a home or office building basement offers more protection than the first floor of a building. The more distance between you and the fallout particles, the better.

The three factors for protecting oneself from radiation and fallout are distance, shielding and time. Petroleum refineries, electrical power plants, and chemical plants.Manufacturing, industrial, technology, and financial centers.Important transportation and communication centers.Centers of government such as Washington, DC, and state capitals.Strategic missile sites and military bases.

Nuclear fallout shelters