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Nuclear Weapons Today

Nuclear Weapons Today

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Nuclear Weapons Today

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  1. Nuclear Weapons Today A presentation prepared by the Medical Association for Prevention of War

  2. Nuclear Weapons Today • The Weapons • The Effects • The Locations • The International Response MAPW (Australia) Nuclear Weapons 2006

  3. The Basics

  4. Nuclear Weapon Cores • Fission weapons require “fissile isotopes” • Most important - plutonium-239 (Pu-239) and uranium-235 (U-235) • Some weapons are made from both isotopes • Basic nuclear weapons rely on nuclear fission chain reaction to produce large amount of energy in a very short time MAPW (Australia) Nuclear Weapons 2006

  5. Nuclear Explosions • Explosive power measured by the mass equivalent of TNT: • A 1 kiloton bomb has an explosive yield equivalent to 1000 tons of TNT • A 1 megaton bomb has an explosive yield equivalent to 1,000,000 tons of TNT MAPW (Australia) Nuclear Weapons 2006

  6. Plutonium • Weapons grade - produced in military plutonium-production reactors specifically for nuclear weapons use • Reactor grade - produced in all nuclear-power reactors • For electricity production, but can be used to make weapons MAPW (Australia) Nuclear Weapons 2006

  7. Plutonium • Powerful nuclear explosive • Highly radioactive and toxic • The half-life of plutonium is 24,500 years • Remains hazardous for 250,000 years MAPW (Australia) Nuclear Weapons 2006

  8. Uranium • Naturally occurring uranium contains 0.7% U-235 • Weapons use highly-enriched uranium (HEU) - proportion of U-235 increased • Weapons grade - usually enriched to greater than 90%, but lower percentages still useable MAPW (Australia) Nuclear Weapons 2006

  9. Separated Plutonium Stocks MAPW (Australia) Nuclear Weapons 2006

  10. Estimated HEU stocks MAPW (Australia) Nuclear Weapons 2006

  11. Core requirements • A 20 kt nuclear bomb requires: • 4-5 kg of weapons grade plutonium OR • 10-15 kg of weapons grade uranium • A 1kt nuclear weapon could be made with: • 1 kg of weapons-grade plutonium OR • 2.5 kg of weapons-grade uranium MAPW (Australia) Nuclear Weapons 2006

  12. The fission process • Nucleus of U-235 or Pu-329 captures a neutron - U-236, Pu-240 nucleus formed. • U-236, Pu-240 very unstable, rapidly split into two (fission) • Neutrons and a large burst of energy are emitted • Complete fissioning of 1 gram of U-235 releases 23,000 kilowatt-hours of heat MAPW (Australia) Nuclear Weapons 2006

  13. The fission process MAPW (Australia) Nuclear Weapons 2006

  14. Critical mass • Each nucleus undergoing fission must produce a neutron that splits another nucleus • Critical mass - the minimum mass of fissile material that can sustain a nuclear fission chain reaction • Sphere is optimum shape MAPW (Australia) Nuclear Weapons 2006

  15. Nuclear explosions • Nuclear explosions occur at super-critical masses • Basic weapons contain fissile material less than critical mass. • Within half a millionth of a second: • Temperatures - hundreds of millions degrees centigrade, and pressures - millions of atmospheres, build up MAPW (Australia) Nuclear Weapons 2006

  16. Fusion • Isotopes of hydrogen - deuterium and tritium • Extremely high temperatures required for reaction to occur • Require a fission bomb to provide energy to initiate reaction • Used mainly to ‘boost’ fission bombs - increase fission rate by providing more high energy neutrons MAPW (Australia) Nuclear Weapons 2006

  17. Main Components Of Nuclear Weapons • High quality, high purity conventional high explosives and reliable detonators • Electronic circuits • A tamper and neutron reflector • A core of fissile material • A neutron source MAPW (Australia) Nuclear Weapons 2006

  18. Detonation techniques Gun technique • Only used with HEU • Mass of sub-critical HEU fired at another - sum of two masses supercritical • Simple technique • Long assembly time • Hiroshima bomb MAPW (Australia) Nuclear Weapons 2006

  19. Detonation techniques • Implosion technique • 1/10 the assembly time of the gun technique • HEU or plutonium can be used • Fissile core surrounded by conventional high explosives MAPW (Australia) Nuclear Weapons 2006

  20. Detonation techniques • Implosion technique • Explosives detonate and uniformly compress the core and increase its density, making it super-critical • Neutrons also fired into fissile material to encourage fission chain reaction MAPW (Australia) Nuclear Weapons 2006

  21. Delivery Systems: • Gravity Bombs • Ballistic Missile Warheads • Cruise Missile Warheads • Other Forms: • Anti-ballistic Missiles • Anti-submarine Warfare MAPW (Australia) Nuclear Weapons 2006

  22. Tactical vs. Strategic Nuclear Weapons • Tactical: • US and Russian definition - less than 500 km range • Strategic: • Intended to be detonated in other countries, i.e. intercontinental delivery MAPW (Australia) Nuclear Weapons 2006

  23. Launch on Warning (LoW) • Retaliation with nuclear weapons to a perceived nuclear attack by another state • Response to a warning (by radar or satellite sensors) of attacking missiles • Decision must be made in minutes MAPW (Australia) Nuclear Weapons 2006

  24. The Effects of Nuclear Weapons

  25. August 6, 1945 • US detonated a 15 kiloton bomb over Hiroshima, Japan • Deaths – 66,000 • Injuries - 69,000 MAPW (Australia) Nuclear Weapons 2006

  26. August 9, 1945 • US detonated a 21 kiloton bomb over Nagasaki, Japan • Deaths - 73,884 • Injuries - 74,909 • 6.7 million square metres leveled MAPW (Australia) Nuclear Weapons 2006

  27. Hiroshima and Nagasaki • Ground temperatures reached about 7,000 degrees • “Black rain” containing radioactive fallout poured down for hours after the explosions MAPW (Australia) Nuclear Weapons 2006

  28. One-MegatonBombDetonatedInTheAir • Flash • Intense flash of light, a thousand times brighter than lightning • Pulse of heat radiation - sets fire to combustible material 14 km away • Pulse of X-rays, lethal within 3 km MAPW (Australia) Nuclear Weapons 2006

  29. One-MegatonBombDetonatedInThe Air • Fireball • Forms after the ‘flash’ and rises in the air • Can permanently blind people up to 80 km away • All exposed body parts burned deeply within 10 km • Superficial burns within fifteen km MAPW (Australia) Nuclear Weapons 2006

  30. One-MegatonBombDetonatedInThe Air • Blast • Powerful blast wave - starts immediately, but travels slower than the flash and fireball • Destroys everything within 2 km • 100% fatalities within 3 km • 50% of people killed within 8 km • Major damage to buildings within 14 km, windows broken out to 20-30 km MAPW (Australia) Nuclear Weapons 2006

  31. One-MegatonBombDetonatedInThe Air • Blast • Hurricane force winds, first outwards, then inwards • Tornado force winds (six hundred km/hr), within four km - can drive glass splinters into people • People picked up and hurled into any object strong enough to be still standing MAPW (Australia) Nuclear Weapons 2006

  32. One-MegatonBombDetonatedInTheAir • Firestorm • Fires started by the first flash coalesce • Cause sufficient updraft to form their own wind, which blows inwards from all sides - increasing the intensity of the fire • Fire uses all available oxygen • “People caught in the open would melt, those in shelters would probably be baked” MAPW (Australia) Nuclear Weapons 2006

  33. One-MegatonBombDetonatedInTheAir • Acute Radiation Exposure • Central nervous system dysfunction • Gastrointestinal damage • Uncontrolled internal bleeding • Bleeding from gums or within the skin • Massive infections • Death MAPW (Australia) Nuclear Weapons 2006

  34. One-MegatonBombDetonatedInTheAir • Delayed Radiation • Everything in vicinity of explosion radioactive • Hiroshima - radioactive rainstorms • 1/3 of original fissile material not destroyed • Widespread contamination • Increased risk of developing cancer for survivors MAPW (Australia) Nuclear Weapons 2006

  35. One-MegatonBombDetonatedInTheAir • In case of a nuclear bomb - don’t bother to call your doctor • No significant medical response possible • Hospitals destroyed, most health care providers killed MAPW (Australia) Nuclear Weapons 2006

  36. One-MegatonBombDetonatedInTheAir • Medical response barriers • No electricity, water or telephone service • No drugs, sterile IV solutions, bandages • Impassable roads, inaccessible areas • Overloading of emergency/ hospital services in surrounding areas • Rescuers risk radiation exposure MAPW (Australia) Nuclear Weapons 2006

  37. One-MegatonBombDetonatedInTheAir • Medical problems: one city of 1-2 million • Fifty times more severe burns than burn beds in North America • A year’s supply of blood for transfusions needed immediately • Bottlenecks and delays due to the need for radioactivity assays • Most of injured die, even from easily treated injuries MAPW (Australia) Nuclear Weapons 2006

  38. One-Megaton Bomb Detonated At Ground-Level • Enormous crater - 400 metres wide and 70 metres deep • Major fallout of radioactive particulates, potentially lethal hundreds of kilometres downwind • Area of blast damage and immediate deaths about one half of air detonation scenario • More deaths days to weeks after bomb due to radiation sickness from fallout MAPW (Australia) Nuclear Weapons 2006

  39. Effect Of Nuclear War • Many nuclear bombs exploded • Radioactive contamination of whole continents • Permanent large scale damage to environment • Nuclear winter MAPW (Australia) Nuclear Weapons 2006

  40. Nuclear Winter • Airborne contaminants absorb and reflect the sun’s rays • Results in an extended period of semi-darkness and freezing temperatures • Potentially generated from less than 100 detonations MAPW (Australia) Nuclear Weapons 2006

  41. Nuclear Winter The view of the Earth from Apollo 10 (18 May 1969) from 26,000 nautical miles on its journey to the Moon MAPW (Australia) Nuclear Weapons 2006

  42. Nuclear Winter This is what the world would look like after a large-scale nuclear holocaust MAPW (Australia) Nuclear Weapons 2006

  43. Nuclear Winter • Nuclear winter could occur with detonation of 100 nuclear warheads over major cities • 30,000 weapons currently, deployed – 90% reduction of deployed weapons could still cause nuclear winter • This puts nuclear weapons are in a league of their own MAPW (Australia) Nuclear Weapons 2006

  44. Nuclear Weapons Testing

  45. Nuclear Testing • 2,058 nuclear test explosions by 8 countries: • United States – 1,030 • Russia (USSR) - 715 • France - 210 • United Kingdom - 45 • China - 45 • India - 7 • Pakistan - 6 MAPW (Australia) Nuclear Weapons 2006

  46. Effects of Nuclear Testing • 2.4 million people estimated to die from cancer as a result of nuclear testing • Tests sites around the world contaminated MAPW (Australia) Nuclear Weapons 2006

  47. Nuclear Terrorism

  48. Nuclear Terrorism • Only 20kg of HEU and 10kg of Plutonium needed • Possibilities: -primitive nuclear explosive -attacking a nuclear-power reactor -nuclear weapon -transport attack -“dirty bomb” MAPW (Australia) Nuclear Weapons 2006

  49. Nuclear Material Availability • Fissile materials are not controlled or accounted for effectively • At least 40 kg of weapons-usable uranium and plutonium has been stolen • Only 1/3 of an estimated 600 tonnes of weapons-usable material in the former USSR has been secured MAPW (Australia) Nuclear Weapons 2006

  50. Terrorism And Nuclear Energy • The International Atomic Energy Agency has confirmed that current nuclear power plants are structurally vulnerable against the Sept. 11 attack scenario • Over 120 documented cases of nuclear sabotage • Credible threats reported by security agencies MAPW (Australia) Nuclear Weapons 2006