Nuclear power is the use of nuclear reaction that release nuclear energy to generate heat, which most frequently is then used in steam turbine to produce electricity in a nuclear power plant. Nuclear is non-emission source of energy that is useful for our life. Except we lost control of it or even worst, nuclear weapon. Most of us have known the history of Hiroshima and Nagasaki when America dropped two atomic bombs on it. What happened there is something that makes an impression on Japanese mind, makes it a nightmare even to entire human on the world. Millions of people passed away in a single blast. Nuclear bomb no similar effect to grenade, nuclear bomb has additional deadly effect even you don’t in blast effect. Here is the effect of nuclear bomb when it explodes.

1. Blast damage

The first effect to you is blast damage. The Blast itself contains 40–50% of total energy when nuclear bomb is exploded. Most of all destruction is caused by blast effect which hit everything in range. For air bursts at or near sea-level, 50–60% of the explosion’s energy goes into the blast wave, depending on the size and the yield of the bomb. As a general rule, the blast fraction is higher for low yield weapons. Furthermore, it decreases at high altitudes because there is less air mass to absorb radiation energy and convert it into a blast. This effect is most important for altitudes above 30  km, corresponding to less than 1 percent of sea-level air density.

Acting on the human body, the shock waves cause pressure waves through the tissues. These waves mostly damage junctions between tissues of different densities (bone and muscle) or the interface between tissue and air. Lungs and the abdominal cavity, which contain air, are particularly injured. The damage causes severe hemorrhaging or air embolisms, either of which can be rapidly fatal. The over pressure estimated to damage lungs is about 70 kPa. Some eardrums would probably rupture around 22 kPa (0.2 atm) and half would rupture between 90 and 130 kPa (0.9 to 1.2 atm).

2. Thermal Radiation

Nuclear weapons emit large amounts of Thermal Radiation as visible, infrared, and ultraviolet light, to which the atmosphere is largely transparent. This is known as “Flash”. Thermal radiation accounts for between 35–45% of the energy released in the explosion, depending on the yield of the device.

There are two types of eye injuries from the thermal radiation of a weapon:

Flash blindness is caused by the initial brilliant flash of light produced by the nuclear detonation. More light energy is received on the retina than can be tolerated, but less than is required for irreversible injury. The retina is particularly susceptible to visible and short wavelength infrared light since this part of the electromagnetic spectrum is focused by the lens on the retina. The result is bleaching of the visual pigments a Burns visible on a woman in Hiroshima during the blast. Darker colors of her kimono at the time of detonation correspond to clearly visible burns on the skin which touched parts of the garment exposed to thermal radiation. Since kimonos are not form-fitting attire, some parts not directly touching her skin are visible as breaks in the pattern, and the tighter-fitting areas approaching the waistline have a much more well-defined pattern.

When thermal radiation strikes an object, part will be reflected, part transmitted, and the rest absorbed. The fraction that is absorbed depends on the nature and color of the material. A thin material may transmit a lot. A light-colored object may reflect much of the incident radiation and thus escape damage, like anti-flash white paint. The absorbed thermal radiation raises the temperature of the surface and results in scorching, charring, and burning of wood, paper, fabrics, etc. If the material is a poor thermal conductor, the heat is confined to the surface of the material.

The thermal pulse also is responsible for warming the atmospheric nitrogen close to the bomb and causing the creation of atmospheric NOx smog components. This, as part of the mushroom cloud, is shot into the stratosphere where it is responsible for dissociating ozone there, in exactly the same way as combustion NOx compounds do. The amount created depends on the yield of the explosion and the blast’s environment.

3. Electromagnetic pulse

Gamma rays from a nuclear explosion produce high energy electrons through Compton scattering. For high altitude nuclear explosions, these electrons are captured in the Earth’s magnetic field at altitudes between twenty and forty kilometers where they interact with the Earth’s magnetic field to produce a coherent nuclear electromagnetic pulse (NEMP) which lasts about one millisecond. Secondary effects may last for more than a second.

The pulse is powerful enough to cause moderately long metal objects (such as cables) to act as antennas and generate high voltages due to interactions with the electromagnetic pulse. These voltages can destroy unshielded electronics. There are no known biological effects of EMP. The ionized air also disrupts radio traffic that would normally bounce off the ionosphere.

4. Radar blackout

The heat of the explosion causes air in the vicinity to become ionized, creating the fireball. The free electrons in the fireball affect radio waves, especially at lower frequencies. This causes a large area of the sky to become opaque to radar, especially those operating in the VHF and UHF frequencies, which is common for long-range early warning radars. The effect is less for higher frequencies in the microwave region, as well as lasting a shorter time – the effect falls off both in strength and the affected frequencies as the fireball cools and the electrons begin to re-form onto free nuclei.

A second blackout effect is caused by the emission of beta particles from the fission products. These can travel long distances, following the Earth’s magnetic field lines. When they reach the upper atmosphere they cause ionization similar to the fireball, but over a wider area. Calculations demonstrate that one megaton of fission, typical of a two megaton H-bomb, will create enough beta radiation to blackout an area 400 kilometres (250 mi) across for five minutes. Careful selection of the burst altitudes and locations can produce an extremely effective radar-blanking effect. The physical effects giving rise to blackouts are those that also cause EMP, which itself can cause power blackouts. The two effects are otherwise unrelated, and the similar naming can be confusing.

5. Ionizing radiation

About 5% of the energy released in a nuclear air burst is in the form of ionizing radiation: neutrons, gamma rays, alpha particles and electrons moving at speeds up to the speed of light. Gamma rays are high energy electromagnetic radiation; the others are particles that move slower than light. The neutrons result almost exclusively from the fission and fusion reactions, while the initial gamma radiation includes that arising from these reactions as well as that resulting from the decay of short-lived fission products.About 5% of the energy released in a nuclear air burst is in the form of ionizing radiation: neutrons, gamma rays, alpha particles and electrons moving at speeds up to the speed of light. Gamma rays are high energy electromagnetic radiation; the others are particles that move slower than light. The neutrons result almost exclusively from the fission and fusion reactions, while the initial gamma radiation includes that arising from these reactions as well as that resulting from the decay of short-lived fission products.

Ionizing radiation is not detectable by human senses, so radiation detection instruments such as Geiger counters must be used to indicate its presence and measure it. However, high intensities can cause emission of visible light upon interaction with matter, such as in Cherenkov radiation and radio luminescence. Ionizing radiation is used in a wide variety of fields such as medicine, nuclear power, research, manufacturing, construction, and many other areas, but presents a health hazard if proper measures against undesired exposure are not followed. Exposure to ionizing radiation causes damage to living tissue and can result in radiation burns, cell damage, radiation sickness, cancer, and death.

6. Earthquake

The pressure wave from an underground explosion will propagate through the ground and cause a minor earthquake. Theory suggests that a nuclear explosion could trigger fault rupture and cause a major quake at distances within a few tens of kilometers from the shot point.

That’s all effects caused by nuclear bomb. From there we know that the nuclear bomb is terrifying thing that we should not make and even it’s better not exist on the world. When it explode, it will threatening all existence. I hope you understand and get educated about nuclear.