Weapon Effects

Questions:

  1. Calculate the EMT of the following weapons: 50 Mt, 10 Mt, 1 Mt, 100 Kt, 10 Kt.
  2. How much energy is contained in 1 Mt of TNT?
  3. If the overpressure is 20 psi, what is the associated wind velocity?
  4. What is the Mach Stem?
  5. Why is an overpressure of 'only' 5 p.s.i. likely to result in a 50% mortality rate for the occupants of residential structures?
  6. The overpressure for a 1-Kt ground burst is 10 p.s.i. at 1100 feet. What is the distance from ground zero will result in the same overpressure for a 64-Kt bomb?
  7. What fraction of the total energy released by a thermonuclear bomb goes into thermal radiation? Blast energy?
  8. What is the temperature of the surface of the fireball when it is at its maximum extent?
  9. At a distance of about seven miles from the burst point of a 1 Mt bomb, which effect is most dangerous to humans; blast or thermal radiation? Why?
  10. Will unprotected newspaper ignite if located one mile from a 10 megaton explosion?
  11. How far from a 10 Kt ground burst must you be in order for the pressure to be less than 1 p.s.i.?
  12. What are some of the biological hazards from fallout?
  13. What are some of the long-term radiation effects from a nuclear explosion?
  14. How many rems would produce mild radiation sickness?
  15. Discuss the predictions of the TTAPS study.
  16. Define delayed fallout.
  17. What effect would a nuclear exchange have on the ozone layer?
  18. What is the maximum radius of a fireball produced by a 100 Kt nuclear weapon?
  19. Why is strontium 90 a particularly dangerous component of delayed fallout?
  20. How are gamma rays emitted during a nuclear explosion?
  21. What are the effects of a High Altitude EMP?
  22. Give a short explanation of the relative importance of each of the four basic effects of a nuclear explosion for a 10 Kt bomb and a 10 Mt bomb.

Answers:

  1. Calculate the EMT of the following weapons: 50 Mt, 10 Mt, 1 Mt, 100 Kt, 10 Kt.

    EMT = (Mt.)2/3
    13.6 Mt. , 4.6 Mt., 1 Mt., 22 Kt. (.022 Mt.), 4.6 Kt. (.0046 Mt.).
    This formula measures the destructive capability of the weapon. The overpressure decreases inversely as the cube of the radius, while the area of destruction increases with the square of the radius.

  2. How much energy is contained in 1 Mt of TNT?

    1 Kt = 4.18 × 1012 joules 1 Mt = 4.18 × 1015 joules

  3. If the overpressure is 20 psi, what is the associated wind velocity?

    An overpressure of 20 psi will produce a maximum wind velocity of 502 mph.

  4. What is the Mach Stem?

    When the shock wave reflects from hitting the earth's surface and recombines with the original shock wave it is called the Mach Stem. The overpressure is now approximately double due to this effect.

  5. Why is an overpressure of 'only' 5 p.s.i. likely to result in a 50% mortality rate for the occupants of residential structures?

    Most blast injuries and fatalities occur because of indirect effects. Objects become missiles. An overpressure of 4 psi can shatter a glass window into hundreds of fragments, traveling about 120 mi/hr, which can cause serious wounds.

  6. The overpressure for a 1-Kt ground burst is 10 p.s.i. at 1100 feet. What is the distance from ground zero will result in the same overpressure for a 64-Kt bomb?

    Using scaling laws;
    d = 1100 ft (64/1)2/3
    = 17,600 ft = 3.33 miles

  7. What fraction of the total energy released by a thermonuclear bomb goes into thermal radiation? Blast energy?

    The blast energy receives about 50% of the total energy, while the thermal energy receives about 35% of the total energy.

  8. What is the temperature of the surface of the fireball when it is at its maximum extent?

    The temperature of the fireball is about 7,000oC. The surface of the sun is about 5,000°C.

  9. At a distance of about seven miles from the burst point of a 1 Mt bomb, which effect is most dangerous to humans; blast or thermal radiation? Why?

    At a distance of seven miles the thermal effects are: Newspaper and dry leaves ignite, some plastics melt, 3rd degree burns, flash blindness and retinal burns in humans.
    The blast effects: people injured by flying glass and debris, winds are about 70 mi/hr.
    The thermal effects outweigh the blast effects slightly.

  10. Will unprotected newspaper ignite if located one mile from a 10 megaton explosion?

    Using the slant range equation
    6,0002 + 36,9602 = d2
    d = 37,444 ft = 7.09 mi

    Using scaling laws
    d= 7.09 mi (.1)2/3 = 1.52 miles
    Yes, enough thermal radiation is present to ignite the newspaper.

  11. What are some of the biological hazards from fallout?

    Some of the biological hazards of fallout are:
    Strontium 90 is a bone seeker that is chemically similar to calcium. It can cause tumors, leukemia and other related blood disorders.
    Cesium 137 behaves like potassium in the body. It can cause genetic damage.
    Carbon 14 in the gonads can contribute to genetic damage.
    Tritium is an isotope of hydrogen that can lead to lung cancer.
    Plutonium can cause lung and bone tumors. Ingestion of as little as one microgram of plutonium-a barely visible speck-is a serious health hazard.
    When ingested concentrations of Iodine 131 build in the thyroid gland, this can lead to hypothyroidism.

  12. What are some of the long-term radiation effects from a nuclear explosion?

    Some long-term radiation effects are: Blood disorders, cataracts, malignant tumors, and genetic defects.

  13. How many rems would produce mild radiation sickness?

    Mild radiation sickness is produced by 100-200 rems of whole body irradiation.

  14. Discuss the predictions of the TTAPS study.

    The smoke from burning cities and forests caused by a nuclear exchange would create a smoke cloud that would "drastically reduce the amount of sunlight reaching the earth's surface." This could reduce the Earth's temperature possibly below the freezing point of water. World wide famines would insue, as well as a multitude of other effects on the ecosystem.

  15. Define delayed fallout.

    Delayed fallout is defined as that which occurs days or years later.

  16. What effect would a nuclear exchange have on the ozone layer?

    A nuclear exchange would have a serious effect on the ozone layer. An exchange would introduce 5 to 50 times more nitrous oxide than is presently contained in the atmosphere. This NO would be injected into sthe stratosphere and the following reactions would occur:

    NO + O3 → NO2 + O2
    O3 + light → O2 + O
    O + NO2 → NO + O3
    net 2O3 → 3O2

  17. What is the maximum radius of a fireball produced by a 100 Kt nuclear weapon?

    R = 145 Y0.39 R = feet Y = kilotons Y = 100 Kt R = 873 feet = .165 mi

  18. Why is strontium 90 a particularly dangerous component of delayed fallout?

    Strontium 90 is a bone seeker that is chemically similar to calcium. It can cause tumors, leukemia and other related blood disorders.

  19. How are gamma rays emitted during a nuclear explosion?

    Gamma radiation is given off when a nucleus in an excited state returns to its ground state.

  20. What are the effects of a High Altitude EMP?

    A high altitude nuclear explosion over a populated area, such as the United States, can cause massive circuit damage. It could destroy much of a nation's telecommunications and computers, wipe out the electric power grid, transistorized ignition systems in vehicles, and anything electronic.

  21. Give a short explanation of the relative importance of each of the four basic effects of a nuclear explosion for a 10 Kt bomb and a 10 Mt bomb.

    In a 10 Mt explosion the blast and thermal effects have a greater range than that of gamma and neutron radiation's. In a 10 Kt, it is reversed. The gamma and neutron radiation are the farthest reaching of the effects. Thus Enhanced Radiation Weapons (ERW), neutron bombs, were developed.