When a nuclear explosion occurs, blast radiation, and heat or thermal effects will occur. When a nuclear weapon detonates at low altitudes, a fireball results from the sudden release of immense quantities of energy. The initial temperature of the fireball ranges into millions of degrees, and the initial pressure ranges to millions of atmospheres. Characteristics of nuclear explosions and their effects on Soldiers, equipment, and supplies, and hasty measures for protection against nuclear attacks will be discussed in this section.
13-47. Nuclear explosions are comprised of the following:
BLAST (INTENSE SHOCK WAVE)
13-48. Blast produces an intense shock wave and high winds, causing debris to fly. The force of a nuclear blast can collapse shelters and fighting positions.
THERMAL RADIATION (HEAT AND LIGHT)
13-49. Thermal radiation starts fires and causes burns. The bright flash at the time of the explosion can cause a temporary loss of vision or permanent eye damage if you look at the explosion, especially at night.
NUCLEAR RADIATION (RADIOACTIVE MATERIAL)
13-50. Nuclear radiation can cause casualties and delay movements. It may last for days and cover large areas of terrain. It occurs in two stages:
13-51. This type of radiation emits directly from the fireball in the first minute after the explosion. It travels at the speed of light along straight lines and has high penetrating power.
13-52. This type of radiation lingers after the first minute. It comes from the radioactive material originally in a nuclear weapon or from material, such as soil and equipment, made radioactive by the nuclear explosion.
13-53. An EMP is a massive surge of electrical power. It is created the instant a nuclear detonation occurs, and it travels at the speed of light in all directions. It can damage solid state components of electrical equipment, such as radios, radar, computers, vehicles–and weapon systems. You can protect equipment by disconnecting it from its power source and placing it in or behind some type of shielding material, such as an armored vehicle or dirt wall, out of the line of sight from the burst. Without warning, there is no way for you to protect your equipment.
13-54. Radiation is the only direct nuclear effect that lingers after the explosion. As it cannot be detected by the senses, use radiac equipment to detect its presence (FM 3-11.3).
RADIAC SET AN/VDR 2
13-55. The AN/VDR 2 is used to perform ground radiological surveys in vehicles or in the dismounted mode by individual Soldiers as a handheld instrument (Figure 13-12). The set can also provide a quantitative measure of radiation to decontaminate personnel, equipment, and supplies. The set includes an audible and/or visual alarm that is compatible with vehicular nuclear, biological, and chemical protective systems in armored vehicles and also interfaces with vehicular power systems and intercoms.
RADIAC SET AN/UDR 13
13-56. The AN/UDR 13 is a compact, handheld, or pocket carried, tactical device that can measure prompt gamma/neutron doses from a nuclear event, plus gamma dose and dose rate from nuclear fallout (Figure 13-13). A push-button pad enables mode selection, functional control, and the setting of audio and visual alarm thresholds for both dose rate and mission dose. A sleep mode with automatic wakeup lengthens battery life. The LCD provides data readout and warning and mode messages.
13-57. If detection equipment is unavailable and you suspect that you are contaminated, decontaminate as required. Procedures for decontamination operations can be found in FM 3-11.5. Radiological contamination can usually be removed by brushing or scraping. When feasible, move out of the contaminated area.
13-58. If your unit must remain in the contaminated area, you should stay in a dug-in position with OHC. If you have time, brush or scoop away the top inch of soil from your fighting position to lower the amount of radiological contamination affecting you. When time does not permit constructing a well prepared OHC, use a poncho. Stay under cover. When the fallout is over, brush contamination off yourself and your equipment. Use water to flush away radiological contamination. However, control the runoff by using drainage ditches that flow into a sump. As soon as mission permits, wash yourself and your equipment. Remember, you have not destroyed the contamination; you have just moved it. The runoff will still be hazardous.
13-59. Blasts, and thermal and nuclear radiation causes nuclear casualties. Except for radiation casualties, treat nuclear casualties the same as conventional casualties. Wounds caused by blast are similar to other combat wounds. Thermal burns are treated as any other type of burn. The exposure of the human body to nuclear radiation causes damage to the cells in all parts of the body. This damage is the cause of “radiation sickness.” The severity of this sickness depends on the radiation dose received, the length of exposure, and the condition of the body at the time. The early symptoms of radiation sickness will usually appear 1 to 6 hours after exposure. Those symptoms may include headache, nausea, vomiting, and diarrhea. Early symptoms may then be followed by a latent period in which the symptoms disappear. There is no first aid for you once you have been exposed to nuclear radiation. The only help is to get as comfortable as possible while undergoing the early symptoms. If the radiation dose was small, the symptoms, if any, will probably go away and not recur. If the symptoms recur after a latent period, you should go to an aid station. A blast can crush sealed or partly sealed objects like food cans, barrels, fuel tanks, and helicopters. Rubble from buildings being knocked down can bury supplies and equipment. Heat can ignite dry wood, fuel, tarpaulins, and other flammable material. Light can damage eyesight. Radiation can contaminate food and water.
13-60. An attack occurring without warning is immediately noticeable. The first indication will be very intense light. Heat and initial radiation come with the light, and the blast follows within seconds. Nuclear attack indicators are unmistakable. The bright flash, enormous explosion, high winds, and mushroom shaped cloud clearly indicate a nuclear attack. An enemy attack would normally come without warning. Initial actions must, therefore, be automatic and instinctive. The best hasty protection against a nuclear attack is to take cover behind a hill or in a fighting position, culvert, or ditch. Time available to take protective action will be minimal. When in a fighting position, you can take additional precautions. The fighting position puts more earth between you and the potential source of radiation. You can curl up on one side, but the best position is on the back with knees drawn up to the chest. This position may seem vulnerable, but the arms and legs are more radiation resistant and will protect the head and trunk. However, if you’re exposed while in the open when a detonation occurs, you should do the following:
- Drop face down immediately, with your feet facing the blast. This will lessen the possibility of heat and blast injuries to your head, face, and neck. A log, a large rock, or any depression in the earth’s surface provides some protection.
- Close eyes.
- Protect exposed skin from heat by putting hands and arms under or near the body and keeping the helmet on.
- Remain facedown until the blast wave passes and debris stops falling.
- Remain calm, check for injury, check weapons and equipment for damage, and prepare to continue the mission.