Radioactive Fallout and Shelter pt2-2 1965 HEW Civil Defense

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• published: 14 Apr 2012
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more at http://scitech.quickfound.net/ "Teaches the individual how to take care of his medical and health needs in time of disaster when medical assistance might not be readily available. Presents instructions on radioactive fallout and shelter. Discusses the effects of radiation on people and emphasizes protective procedures against radiation." Public domain film slightly cropped to remove uneven edges, with the aspect ratio corrected, and mild video noise reduction applied. The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and equalization (the resulting sound, though not perfect, is far less noisy than the original). Split with MKVmerge GUI (part of MKVToolNix), the same software can recombine the downloaded parts (in mp4 format): http://www.bunkus.org/videotools/mkvtoolnix/doc/mkvmerge-gui.html part 2: http://en.wikipedia.org/wiki/Fallout_shelter A fallout shelter is an enclosed space specially designed to protect occupants from radioactive debris or fallout resulting from a nuclear explosion. Many such shelters were constructed as civil defense measures during the Cold War. During a nuclear explosion, matter vaporized in the resulting fireball is exposed to neutrons from the explosion, absorbs them, and becomes radioactive. When this material condenses in the rain, it forms dust and light sandy materials that resembles ground pumice. The fallout emits alpha and beta particles, as well as gamma rays. Much of this highly radioactive material then falls to earth, subjecting anything within the line of sight to radiation, a significant hazard. A fallout shelter is designed to allow its occupants to minimize exposure to harmful fallout until radioactivity has decayed to a safer level. Although many shelters still exist, many even being used as museums, virtually all fallout shelters have been decommissioned since the fall of the Soviet Union in 1991... Shielding 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 of packed dirt, reducing gamma rays by 1024 times. Usually, an expedient purpose-built fallout shelter is a trench; with a strong roof buried by c. 1 m (3 ft) of dirt. The two ends of the trench have ramps or entrances at right angles to the trench, so that gamma rays cannot enter (they can travel only in straight lines). To make the overburden waterproof (in case of rain), a plastic sheet should be buried a few inches below the surface and held down with rocks or bricks. Blast doors are designed to absorb the shock wave of a nuclear blast, bending and then returning to their original shape. Climate control Dry earth is a reasonably good thermal insulator, and over several weeks of habitation, a shelter will become too hot for comfort. The simplest form of effective fan to cool a shelter is a wide, heavy frame with flaps that swing in the shelter's doorway and can be swung from hinges on the ceiling. The flaps open in one direction and close in the other, pumping air. Attach a rope, and take turns swinging it. (This is a Kearny Air Pump, or KAP, named after the inventor.) Unfiltered air is safe, since the most dangerous fallout has the consistency of sand or finely ground pumice. Such large particles are not easily ingested into the soft tissues of the body, so extensive filters are not required. Any exposure to fine dust is far less hazardous than exposure to the gamma from the fallout outside the shelter. Dust fine enough to pass the entrance will probably pass through the shelter. Collective NBC protection system Usually blast protection valves are installed at the air-inlet and air outlet to prevent the penetration of blast waves caused by explosions outside of the shelter. A positive pressure (overpressure) is created in the shelter by pulling filtered air into the protected area. The air is filtered by the means of NBC-filters (NBC = Nuclear, Biological and Chemical filters)...