Survival 101: Disasters and Disaster Shelters

In the detonation of a one megaton size weapon (which is roughly equivalent to 1 million tons of TNT), the fireball grows to 440 feet in just a fraction of a second. In 10 seconds, the fireball is over a mile wide. At the same time the fireball is forming and growing, a high-pressure wave develops and moves outward in all directions. This wave of air causes a huge increase in air pressure. At one-quarter mile from the crater edge, the overpressures are about 200 psi. It is not expected that nuclear weapons with a greater yield than one megaton would be used against the civilian population. We are, therefore, limiting our discussion of blast effects to that yield.

At approximately 4 miles from the epicenter, the winds are 165 mph and the overpressure is approximately 5 psi. Most homes would be destroyed, and very little blast effect protection would be found in a basement shelter at that distance. At 6 and 7 miles from the epicenter, there would be moderate damage to residences and the likelihood of surviving in a basement is increased.

People housed in hardened blast shelters and radiation shelters, such as are built by Utah Shelter Systems, would be expected to survive all NBC weapons effects at ground zero from an air burst (50 psi), and at one quarter mile from the crater edge from a one megaton yield ground burst. At that proximity, an 8 ft. diameter shelter must have at least 8 feet of dirt cover. A 10-foot diameter shelter must have at least 10 feet of dirt cover overhead. Each person must have approximately 10 square feet of shelter space for short-term survival (up to 2 weeks). Double this space requirement if the shelter must be used for longer periods.

The electromagnetic pulse (EMP) is created by explosions from both nuclear and conventional weapons. The size and strength of the electromagnetic pulse is dependent on weapon design and height of burst. Collectors, such as long runs of cable, house wiring, conduit, large antennas, overhead power and telephone lines, railroad tracks, etc., gather the energy from the EMP pulse in the form of a strong current and voltage surge. All solid-state electronics are vulnerable to this energy surge. The equipment does not have to be attached directly to the collector in order to be damaged. It's possible for a collector to gather as much as a joule of energy from a one megaton, high altitude explosion. The fact that a small fraction of a joule can cause permanent damage to electronic devices would indicate that an EMP could destroy much of the nation’s unprotected electrical equipment, including computers, some automobile ignition systems, emergency response systems, telephone and radio communications, airline communications, navigational aids, and water purification systems. It is estimated that about 95% of our radio stations would immediately lose transmission from an electro magnetic pulse. The EMP from one nuclear weapon, detonated at that elevation, could affect an area of a thousand miles in diameter, and it would take decades to make the needed repairs.

Electrical Equipment Protection

EMP protection of electrical equipment is achieved by placing the equipment into faraday cages (metal containers). All critical electronics should be protected in these cages. The lids of the containers should have good metal to metal contact. All paint and gaskets should be removed from the lid closure area. EMP protection for continually-functioning equipment is expensive and difficult but achievable; it requires wave guides, EMP filters, and metal cladding of cables and wires.

Power-Drop Alarms

Many strategists believe that a full-scale war would be initiated by an EMP detonated from a satellite at an elevation of about 200 miles. A nuclear bomb detonated at that altitude will not damage living tissue, will not cause significant radiation fallout and is not a health threat to the population; therefore, EMP effect protection is not needed for people. The enemy’s purpose for initiating an EMP would be to damage critical electrical circuitry in our retaliatory defense weapons and our military communications capabilities. Immediately after the initial EMP explosion, SLBM's and ICBM's would be launched against targets in the United States. An ICBM from Russia would reach the center of the continental United States in about 25 minutes. A missile from a submarine could reach us in 8 minutes. A power drop alarm would give notice of a possible EMP attack. The 25 minutes that the power drop alarm will give could mean the difference between life and death.

Whenever a power drop is detected, care should be taken to test telephones, radio stations, and other equipment for loss of function. Many radio stations have alternate power sources, but only about 5% of our radio stations have been hardened against the EMP. If, after checking a battery-powered radio, you find that most of the radio stations are not functioning, go to your underground shelter and remain there for 8 to 10 hours.

Make your own alarm

If the attack occurs during the night, a simple power-drop alarm would alert you to the power failure. Alarms can be constructed from a motorcycle horn, a 12-volt battery, a relay switch, and a flasher. The negative line from the battery was connected to the 12 V DC horn. When the 110 V AC currant fails, the relay closes the circuit, which activates the horn. Add a switch to the positive line from the battery to the horn so the horn can be turned off after activation. This alarm could pose an electrical shock hazard and should only be constructed by a certified electrician.

EMP weapons can be launched from satellites, by intercontinental ballistic missiles (ICBMs), submarine launched ballistic missiles (SLBMs) or could even be deployed from surface to air missiles launched from a ship. If Iran's, Shahab-3 ballistic missile, were armed with a nuclear weapon and launched from a ship in our costal waters, the missile could reach altitudes capable of destroying the electrical grid in about 1/3 of the nation. The cascading effect of an already stressed grid could severely damage much of the rest of the nation’s grid. North Korea, an ally of Iran, boasts that they already have nuclear weapons with ballistic missiles capable of causing a destructive electromagnetic pulse.

The thermal effect can result in both blindness and physical burns.

At 6 to 8 miles from the blast, the thermal pulse will cause third degree burns to anyone that is unshielded, and it would cause second degree burns at a distance of 8 to 10 miles. Even at 10 to 12 miles, where blast is no longer an issue, unprotected individuals would receive 1st degree burns.Thermal protection is extremely important, as burns would greatly complicate an otherwise survivable situation.

Within less than a millionth of a second of the detonation, large amounts of energy in the form of invisible x-rays are absorbed within just a few feet of the atmosphere. This leads to the formation of an extremely hot and luminous mass called the fireball. If we were standing 50 miles away, this fireball would appear to us to be many more times as brilliant as the noonday sun.

Never look directly at the fireball of a nuclear explosion. Because of the focusing action of the lens of the eye, especially at night when our pupils are open, thermal radiation can cause temporary and even permanent blindness. The thermal pulse travels at the speed of light and can last for a fraction of a second, up to several seconds. It also generally travels in straight lines.

Thermal protection is achieved by the ‘drop and cover’ method. If you do have warning, you should take cover behind a large structure, or go to a basement or culvert.