Presentation on Nuclear

Weapons

Saad Abdul WahabM.Sc Applied Chemistry & Chemical Technology (Specialization in Petroleum Technology From University of Karachi)BE Textile, from Synthetic Fiber Development & Application Center.IOSH Managing Safely.Certifications of HSE, EMS-14001, OSHAS-18001, QMS 9001:2008, FSMS-22000:2005, SSCL (17025) by SGS & NILAT.IRCA approved Lead Auditor OHSAS 18001:2004 .HSE Rules & Laws in Industries from SDC.Authorized Safety Instructor from DG Federal Civil Defence Pakistan.

Topics:

• Effects of blast• Area of destruction• Fringe Area• Fall out• Radiation Sequence• Nuclear fission & fusion• Chain Reaction• Radiation• Thermal Burns• Q/A

Nuclear Physics

• Nuclear physics is the field of physics that studies the constituents and

interactions of atomic nuclei. The most commonly known applications of

nuclear physics are nuclear power generation and nuclear

weapons technology, but the research has provided application in many

fields, including those in nuclear medicine and magnetic resonance

imaging, ion implantation in materials engineering, and radiocarbon

dating in geology and archaeology.

• The field of particle physics evolved out of nuclear physics and is typically

taught in close association with nuclear physics.

Effects of Nuclear Explosion

• 1 Direct effects

– 1 Blast damage

– 2 Thermal radiation

• 2 Indirect effects

– 1 Electromagnetic pulse

– 2 Ionizing radiation

– 3 Earthquake

– 4 Summary of the effects

• Little boy (Bomb)

• Angola-gay (Bomber)

Understand the hazards of Nuclear Attacks

• Effects:• The energy released from a nuclear weapon detonated in

the troposphere can be divided into four basic categories:

• Blast—40–50% of total energy

• Thermal radiation—30–50% of total energy

• Ionizing radiation—5% of total energy (more in a neutron bomb)

• Residual radiation—5–10% of total energy

Area of heavy destruction

• Direct Effect:• Much of the destruction caused by a nuclear explosion is due to blast effects. Most

buildings, except reinforced or blast-resistant structures, will suffer moderate damage when subjected to overpressures of only 35.5 kilopascals (kPa) (5.15 pounds-force per square inch or 0.35 atm).

EffectsExplosive yield / Height of Burst

1 kt / 200 m 20 kt / 540 m 1 Mt / 2.0 km 20 Mt / 5.4 km

Blast—effective ground range GR / km

Urban areas completely levelled

(20 psi or 140 kPa)0.2 0.6 2.4 6.4

Destruction of most civilian

buildings (5 psi or 34 kPa)0.6 1.7 6.2 17

Moderate damage to civilian

buildings (1 psi or 6.9 kPa)1.7 4.7 17 47

Railway cars thrown from tracks

and crushed (62 kPa; values for

other than 20 kt are extrapolated

using the cube-root scaling)

≈0.4 1.0 ≈4 ≈10

Thermal radiation—effective ground range GR / km

Conflagration 0.5 2.0 10 30

Third degree burns 0.6 2.5 12 38

Second degree burns 0.8 3.2 15 44

First degree burns 1.1 4.2 19 53

Effects of instant nuclear radiation—effective slant range1 SR / km

Lethal2 total dose (neutrons and

gamma rays)0.8 1.4 2.3 4.7

Total dose for acute radiation

syndrome2 1.2 1.8 2.9 5.4

Nuclear Warfare• Nuclear warfare (sometimes atomic

warfare or thermonuclear warfare), is a military conflict or political strategy in which nuclear weaponry is used to inflict damage on an opponent. Compared to conventional warfare, nuclear warfare can be vastly more destructive in range and extent of damage, and in a much shorter time frame. A major nuclear exchange could have severe long-term effects, primarily from radiation release, but also from the production of high levels of atmospheric pollution leading to a "nuclear winter" that could last for decades, centuries, or even millennia after the initial attack.[1][2] A large nuclear war is considered to bear existential risk for civilization on Earth.[3][4] Importantly however, despite modern civilization being at risk, assuming weapons stockpiles at the previous cold war heights, analysts and physicists have found that billions of humans would nevertheless survive a global thermonuclear war.[5][6][7][8]

• Only two nuclear weapons have been used in the course of warfare, both by the United States near the end of World War II. On August 6, 1945, auranium gun-type device (code name "Little Boy") was detonated over the Japanese city of Hiroshima. Three days later, on August 9, a plutoniumimplosion-type device (code name "Fat Man") was detonated over Nagasaki, Japan. These two bombings resulted in the deaths of approximately 200,000 Japanese people (mostly civilians) from acute injuries sustained in the detonations.

Mushroom cloud from the atomic explosion over Nagasaki rising 60,000 feet into the air on the morning of August 9, 1945.

Fringe Area

• Fringe science is scientific inquiry in an established field of study that

departs significantly from mainstream or orthodox theories, and is classified

in the "fringes" of a credible mainstream academic discipline.

• Three classifications of scientific ideas have been identified (center, frontier,

fringe) with mainstream scientists typically regarding fringe concepts as

highly speculative or even strongly refuted. However, according to

Rosenthal "Accepted science may merge into frontier science, which in turn

may merge into more far-out ideas, or fringe science. Really wild ideas may

be considered beyond the fringe, or pseudoscientific."

Nuclear fallout• Nuclear fallout, or simply fallout, also known as Black Rain, is the residual

radioactive material propelled into the upper atmosphere following a nuclear blastor a nuclear reaction conducted in an unshielded facility, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes, but such dust can also originate from a damaged nuclear plant.

• This radioactive dust, consisting of material either directly vaporized by a nuclear blast or charged by exposure, is a highly dangerous kind of radioactive contamination.

Radiation Sickness

• Acute radiation syndrome (ARS), also known as radiation poisoning, radiation sickness or radiation toxicity, is a constellation of health effects which present within 24 hours of exposure to high amounts of ionizing radiation. The radiation causes cellular degradation due to destruction of cell walls and other key molecular structures within the body; this destruction in turn causes the symptoms. The symptoms can begin within one or two hours and may last for several months. The terms refer to acute medical problems rather than ones that develop after a prolonged period.

• Similar symptoms may appear months to years after exposure as chronic radiation syndrome when the dose rate is too low to cause the acute form. Radiation exposure can also increase the probability of developing some other diseases, mainly different types of cancers. These diseases are sometimes referred to as radiation sickness, but they are never included in the term acute radiation syndrome.

Phase Symptom

Whole-body absorbed dose (Gy)

1–2 Gy 2–6 Gy 6–8 Gy 8–30 GyGreater Than

30 Gy

Immediate

Nausea and vo

miting5–50% 50–100% 75–100% 90–100% 100%

Time of onset 2–6 h 1–2 h 10–60 min < 10 min Minutes

Duration < 24 h 24–48 h < 48 h < 48 hN/A (patients die in

< 48 h)

Diarrhea None None to mild (< 10%) Heavy (> 10%) Heavy (> 95%) Heavy (100%)

Time of onset — 3–8 h 1–3 h < 1 h < 1 h

Headache Slight Mild to moderate (50%) Moderate (80%) Severe (80–90%) Severe (100%)

Time of onset — 4–24 h 3–4 h 1–2 h < 1 h

Fever NoneModerate increase (10-

100%)

Moderate to severe

(100%)Severe (100%) Severe (100%)

Time of onset — 1–3 h < 1 h < 1 h < 1 h

CNS functionNo

impairment

Cognitive impairment

6–20 h

Cognitive impairment >

24 h

Rapid

incapacitation

Seizures, Tremor,

Ataxia, Lethargy

Latent period 28–31 days 7–28 days < 7 days none none

Illness

Mild to

moderate Le

ukopenia

Fatigue

Weakness

Moderate to severe

Leukopenia

Purpura

Hemorrhage

Infections

Epilation after 3 Gy

Severe leukopenia

High fever

Diarrhea

Vomiting

Dizziness and

disorientation

Hypotension

Electrolyte disturbance

Nausea

Vomiting

Severe diarrhea

High fever

Electrolyte

disturbance

Shock

N/A (patients die in

< 48h)

Mortality

Without care 0–5% 5–100% 95–100% 100% 100%

With care 0–5% 5–50% 50–100% 100% 100%

Death 6–8 weeks 4–6 weeks 2–4 weeks 2 days–2 weeks 1–2 days

Nuclear fission• Nuclear fission is the reverse process of fusion. For nuclei heavier than nickel-62 the binding

energy per nucleon decreases with the mass number. It is therefore possible for energy to be

released if a heavy nucleus breaks apart into two lighter ones.

• The process of alpha decay is in essence a special type of spontaneous nuclear fission. This

process produces a highly asymmetrical fission because the four particles which make up the

alpha particle are especially tightly bound to each other, making production of this nucleus in

fission particularly likely.

• For certain of the heaviest nuclei which produce neutrons on fission, and which also easily absorb

neutrons to initiate fission, a self-igniting type of neutron-initiated fission can be obtained, in a so-

called chain reaction. Chain reactions were known in chemistry before physics, and in fact many

familiar processes like fires and chemical explosions are chemical chain reactions. The fission

or "nuclear" chain-reaction, using fission-produced neutrons, is the source of energy for nuclear

power plants and fission type nuclear bombs, such as those detonated by the United

States inHiroshima and Nagasaki, Japan, at the end of World War II. Heavy nuclei such

as uranium and thorium may also undergo spontaneous fission, but they are much more likely to

undergo decay by alpha decay.

• For a neutron-initiated chain-reaction to occur, there must be a critical mass of the element

present in a certain space under certain conditions. The conditions for the smallest critical mass

require the conservation of the emitted neutrons and also their slowing or moderation so there is a

greater cross-section or probabability of them initiating another fission. In two regions

of Oklo, Gabon, Africa, natural nuclear fission reactors were active over 1.5 billion years

ago. Measurements of natural neutrino emission have demonstrated that around half of the heat

emanating from the Earth's core results from radioactive decay. However, it is not known if any of

this results from fission chain-reactions.

Nuclear Fusion

• In nuclear fusion, two low mass nuclei come into very close contact with each other, so that the strong force fuses them. It requires a large amount of energy to overcome the repulsion between the nuclei for the strong or nuclear forces to produce this effect, therefore nuclear fusion can only take place at very high temperatures or high pressures. Once the process succeeds, a very large amount of energy is released and the combined nucleus assumes a lower energy level. The binding energy per nucleon increases with mass number up until nickel-62. Stars like the Sun are powered by the fusion of four protons into a helium nucleus, two positrons, and two neutrinos. The uncontrolled fusion of hydrogen into helium is known as thermonuclear runaway. A frontier in current research at various institutions, for example the Joint European Torus (JET) and ITER, is the development of an economically viable method of using energy from a controlled fusion reaction. Natural nuclear fusion is the origin of the light and energy produced by the core of all stars including our own sun.

Chain Reaction

Fusion Chain Reaction

Radiation

Nuclear radiations• Types of radiation

• Nuclear radiation arises from hundreds of different kinds of unstable atoms. While many exist in nature, the

majority are created in nuclear reactions, Ionizing radiation which can damage living tissue is emitted as the

unstable atoms (radionuclides) change ('decay') spontaneously to become different kinds of atoms.

• The principal kinds of ionizing radiation are:

• Alpha particles

• These are helium nuclei consisting of two protons and two neutrons and are emitted from naturally-occurring

heavy elements such as uranium and radium, as well as from some man-made transuranic elements. They

are intensely ionizing but cannot penetrate the skin, so are dangerous only if emitted inside the body.

• Beta particles

• These are fast-moving electrons emitted by many radioactive elements. They are more penetrating than alpha

particles, but easily shielded – they can be stopped by a few millimetres of wood or aluminium. They can

penetrate a little way into human flesh but are generally less dangerous to people than gamma radiation.

Exposure produces an effect like sunburn, but which is slower to heal. Beta-radioactive substances are also

safe if kept in appropriate sealed containers.

• Gamma rays

• These are high-energy beams much the same as X-rays. They are emitted in many radioactive decays and

are very penetrating, so require more substantial shielding. Gamma rays are the main hazard to people

dealing with sealed radioactive materials used, for example, in industrial gauges and radiotherapy machines.

Radiation dose badges are worn by workers in exposed situations to detect them and hence monitor

exposure. All of us receive about 0.5-1 mSv per year of gamma radiation from cosmic rays and from

rocks, and in some places, much more. Gamma activity in a substance (e.g. rock) can be measured with a

scintillometer or Geiger counter.

• X-rays are also ionizing radiation, virtually identical to gamma rays, but not nuclear in origin.

• Cosmic radiation consists of very energetic particles, mostly protons, which bombard the Earth from outer

space.

Thermal Burns

• A burn is a type of injury to flesh or skin caused

by heat, electricity, chemicals, friction, or radiation. Burns that affect only the

superficial skin are known as superficial or first-degree burns. When

damage penetrates into some of the underlying layers, it is a partial-

thickness or second-degree burn. In a full-thickness or third-degree

burn, the injury extends to all layers of the skin. A fourth-degree burn

additionally involves injury to deeper tissues, such as muscle or bone.

EffectsExplosive yield / Height of Burst

1 kt / 200 m 20 kt / 540 m 1 Mt / 2.0 km 20 Mt / 5.4 km

Blast—effective ground range GR / km

Urban areas completely levelled (20 psi or

140 kPa)0.2 0.6 2.4 6.4

Destruction of most civilian buildings (5 psi

or 34 kPa)0.6 1.7 6.2 17

Moderate damage to civilian buildings (1 psi

or 6.9 kPa)1.7 4.7 17 47

Railway cars thrown from tracks and

crushed (62 kPa; values for other than 20 kt

are extrapolated using the cube-root scaling)

≈0.4 1.0 ≈4 ≈10

Thermal radiation—effective ground range GR / km

Conflagration 0.5 2.0 10 30

Third degree burns 0.6 2.5 12 38

Second degree burns 0.8 3.2 15 44

First degree burns 1.1 4.2 19 53

Effects of instant nuclear radiation—effective slant range1 SR / km

Lethal2 total dose (neutrons and gamma

rays)0.8 1.4 2.3 4.7

Total dose for acute radiation syndrome2 1.2 1.8 2.9 5.4

Prevention (Next Presentation)

– 1 Distance

– 2 Time

– 3 Shielding

– 4 Reduction of incorporation into the human body

– 5 Fractionation of dose

Thank You

• Q/A..??

Email: saadawkhan@yahoo.comCell: 0333-3235554, 0313-2338340

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