Nuclear Accident

A nuclear accident is still possible even though the construction and operation of nuclear power plants are closely monitored and regulated by the Nuclear Regulatory Commission (NRC).

Nuclear Accident

Nuclear power plants use the heat generated from nuclear fission in a contained environment to convert water to steam, which powers generators to produce electricity. It is the by-product of this activity that creates the biggest hazard.

They operate in most states in the country and produce about 20 percent of the nation’s power. Nearly 3 million Americans live within 10 miles of an operating nuclear power plant.

Emergency Response Plans

Local and state governments, federal agencies, and the electric utilities have emergency response plans in the event of a nuclear incident. The United States Nuclear Regulatory Commission regulates commercial nuclear power plants within the US.

The emergency response plans define two “emergency planning zones.”

• One zone covers an area within a 10-mile radius of the plant, where it is possible that people could be harmed by direct radiation exposure.


• The second zone covers a broader area, usually up to a 50-mile radius from the plant, where radioactive materials could contaminate water supplies, food crops, and livestock.

What to do if you are exposed?

Famous Nuclear Accidents

March 11, 2011 Fukushima Daiichi nuclear power plant in Japan confirmed a nuclear accident with resulting in an explosion and radiation leak in the waked of the 9.0 earthquake and major Tsunami that swept 6 miles inland.

Japan declared states of emergency for five nuclear reactors at two power plants after the units lost cooling ability.

The nuclear safety agency reported an emergency at second reactor and have evacuated as many as 170,000 people from the areas around two nuclear power plants and the prime minister has warned residents living within 19 miles to stay inside or risk getting radiation sickness.

After the recent blast radiation detectors showed 11,900 microsieverts of radiation three hours after the blast, up from just 73 microsieverts beforehand. However, health risks are at levels exceeding 100,000 microsieverts.

Fukushima Daiichi Nuclear Emergency Level Upgraded

On March 26, 2011, this accident was upgraded to a Level 5 on a seven-level international scale, putting it on par with the Three Mile Island accident in Pennsylvania in 1979.

• A partial meltdown at Three Mile Island also was ranked a Level 5.


• The Chernobyl accident of 1986, which killed at least 31 people with radiation sickness, raised long-term cancer rates, and spewed radiation for hundreds of miles (kilometers), was ranked a Level 7.

Radiation Exposure

The potential danger from a nuclear accident is exposure to radiation.

Exposure could result from the release of radioactive material from a nuclear plant into the environment, usually characterized by a plume (cloud-like formation) of radioactive gases and particles.

If a complete reactor meltdown, where the uranium core melts through the outer containment shell, were to occur, a wave of radiation would be released, resulting in major, widespread health problems.

The major hazards to people in the vicinity of the plume are radiation exposure to the body from the cloud and particles deposited on the ground, inhalation of radioactive materials, and ingestion of radioactive materials.

Radioactive materials are composed of atoms that are unstable. An unstable atom gives off its excess energy until it becomes stable.

The energy emitted is radiation.

The longer a person is exposed to radiation, the greater the effect. A high exposure to radiation can cause serious illness or death.

Nuclear radiation exposure can also be a risk. Find out what the signs are.

A nuclear blast has an incredibly destructive pressure wave. In fact, this is what creates the most damage initially. Second to that is the radioactive material that contaminates the air, water, and ground. This is one kind of radiation associated with a nuclear bomb. The other is thermal radiation. Thermal radiation is "heat" radiation. It is what causes the first, second and third degree burns on skin (depending upon distance to the explosion site).

A nuclear device can be anything from a weapon on a missile to a small portable nuclear device transported by an individual.

All nuclear devices cause deadly effects when exploded, including blinding light, intense heat (thermal radiation), and secondary fires caused by the destruction.

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Hazards of a Nuclear Accident

The extent, nature, and arrival time of these hazards are difficult to predict.

The geographical dispersion of hazard effects will be defined by the following:

• Size of the device. A more powerful bomb will produce more distant effects.

• Height above the ground the device was detonated. This will determine the extent of blast effects.

• Nature of the surface beneath the explosion. Some materials are more likely to become radioactive and airborne than others. Flat areas are more susceptible to blast effects.

• Existing meteorological conditions. Wind speed and direction will affect arrival time of fallout; precipitation may wash fallout from the atmosphere.

Radioactive Fallout from Nuclear Accident or Blast

Even if individuals are not close enough to the nuclear blast to be affected by the direct impacts, they may be affected by radioactive fallout.

Any nuclear blast results in some fallout.

Blasts that occur near the earth’s surface create much greater amounts of fallout than blasts that occur at higher altitudes. This is because the tremendous heat produced from a nuclear blast causes an up-draft of air that forms the familiar mushroom cloud.

Fallout from a nuclear explosion may be carried by wind currents for hundreds of miles if the right conditions exist. Effects from even a small portable device exploded at ground level can be potentially deadly.

Nuclear radiation cannot be seen, smelled, or otherwise detected by normal senses.

Radiation can only be detected by radiation monitoring devices. This makes radiological emergencies different from other types of emergencies, such as floods or hurricanes.

Monitoring can project the fallout arrival times, which will be announced through official warning channels. However, any increase in surface build-up of gritty dust and dirt should be a warning for taking protective measures.

Electromagnetic Pulse (EMP)

In addition to other effects, a nuclear weapon detonated in or above the earth’s atmosphere can create an electromagnetic pulse (EMP), a high-density electrical field. An EMP acts like a stroke of lightning but is stronger, faster, and shorter.

An EMP can seriously damage electronic devices connected to power sources or antennas. This includes communication systems, computers, electrical appliances, and automobile or aircraft ignition systems.

Additional Resources

Here is a free ebook on Nuclear War Survival Skills