Know Nuclear

Accidents

THREE MILE ISLAND

On March 28, 1979, TMI experienced the most serious accident in U.S. commercial nuclear power plant operating history. However, this event led to no deaths or injuries to plant workers or members of the nearby community. It brought about sweeping changes regarding many areas of nuclear power plant operations – from emergency response planning to reactor operator training. It also caused the U.S. Nuclear Regulatory Commission to tighten and heighten its regulatory oversight.

Today, the Three Mile Island nuclear plant (TMI) generates enough electricity to power a city the size of Philadelphia. Its world class performance record demonstrates the exceptional focus and hard work of the people who safely and efficiently run the plant.

To learn more, click the links below:

The TMI-2 Accident – In Brief
What Happened and What Didn’t in the TMI-2 Accident
The TMI-2 Cleanup: Challenging and Successful
No Radiological Health Effects at TMI
Health Studies Find No Cancer Link to TMI
Frequently Asked Questions

CHERNOBYL

NOW AVAILABLE – Chernobyl: 25 Years Later View/Download: Adobe PDF

On April 26, 1986, an accident occurred at the Chernobyl Nuclear Power Plant near Kiev in the Ukrainian Republic of the Former Soviet Union. With the release of radiation, human casualties, physical damage to the plant and contamination of the surrounding environment, Chernobyl marked the worst accident in the history of nuclear power production. It also demonstrated the importance of strong safety culture, independent regulators, and well designed plants, reinforcing nuclear safety efforts for the years to come.

According to the World Health Organization, the accident led to the fatalities of thirty-six workers. More than 200,000 people in the Ukraine and Belarus Republics were evacuated and resettled as a result of significant fallout from the Chernobyl accident. Land was contaminated in the Ukraine Republic, Belarus Republic, Russia, Europe, and Scandinavia. Recovery efforts continue to be managed by the international community.

The world nuclear community quickly determined that an accident similar to Chernobyl – 4 could not happen in any other type of plant, due to higher design and operational standards outside the Soviet Union. The remaining Chernobyl type reactors throughout the former Soviet bloc were modified for safe operation. Some were shut down. Many are still in operation. Health and Environmental studies are still going on, and will continue into the foreseeable future.

The World Association of Nuclear Operators (WANO) to promote cooperation, was founded as a result of this tragedy.

To learn more, click the links below:

Chernobyl in Brief
What Happened – In Detail
Health Studies of Radiological Impact
Chernobyl Today and in the Future
Chernobyl Myths
Frequently Asked Questions

FUKUSHIMA

On Friday, March 11, 2011, one of the largest earthquakes in the recorded history of the world occurred on the east coast of northern Japan. This earthquake also generated a major tsunami, causing nearly 20,000 deaths. Electricity, gas and water supplies, telecommunications, and railway service were all severely disrupted and in many cases completely shut down. These disruptions severely affected the Fukushima Daiichi nuclear power plant, causing a loss of all on-site and off-site power and a release of radioactive materials from the reactors.

The leadership of the American Nuclear Society commissioned the American Nuclear Society Special Committee on Fukushima to provide a clear and concise explanation of what happened during the Fukushima Daiichi accident, and offer recommendations based on lessons learned from their study of the event. The American Nuclear Society, a professional organization of 11,600 nuclear science and technology professionals, has a strong tradition of advancing nuclear safety, and the Special Committee on Fukushima was organized to further its members’ interests in this important professional obligation.

To view the full report please visit http://fukushima.ans.org/

DID YOU KNOW?

Scientific studies and measurements are clearly indicating that there is no public health hazard from radioactivity originating from the accident that occurred at the Fukushima Daiichi nuclear power plant in March 2011.

While nuclear professionals continue to monitor any potential dose consequences, any effect of radioactivity coming across the Pacific to the United States coast would be negligible,” noted Dr. Michaele Brady Raap, American Nuclear Society Vice-President and President-Elect.

For more information, please review the article, Radiation dose rates now and in the future for residents neighboring restricted areas of the Fukushima Daiichi Nuclear Power Plant,  published by the Proceedings of the National Academy of Sciences of the United States of America.

‎What Happened at Fukushima?


What Type of reactor(s) are at Fukushima?


The reactors at Fukushima were typical BWR-3 (Unit 1) and BWR-4 (Units 2 – 5) designs. Prior to the accident Units 1, 2 and 3 were operating, Unit 4 was defueled, but not operating (planned maintenance), and Units 5 and 6 fueled, but not operating (planned outage).


What lessons were learned from Fukushima?

  • Earthquake design basis adequate
  • Tsunami design basis and emergency planning insufficient for NPP and other key infrastructure
  • Must diversify, increase and secure onsite power supply to avoid core damage


What are U.S. plants doing to prevent such an event at home?

In the three years since the event, which was caused by a catastrophic tsunami, the international nuclear community has rallied together to make sure that help and resources were made available to assist in evaluation, cleanup and radiation monitoring efforts. This effort has enabled the U.S. to enhance safety systems across the U.S. fleet. One of the primary enhancements is the planning for long-term loss of the diesel engines used at the plants.


How many people died at Fukushima?

  • Number of residential buildings damaged or destroyed due to earthquake/tsunami: 475,000
  • Number of people dead due to the earthquake/tsunami:  > 20,000
  • Number of km2 inundated by tsunami: 560 km2 (215 mi2, about the size of Chicago)
  • Number of deaths due to tsunami at the nuclear power plant (NPP): 2
  • Number of deaths due to radiation exposure: 0
  • Number of cases of radiation sickness: 0

Sources: WNA Japanese Report to IAEA, June 2011


What has been done to prevent the spread of radioactive materials?

Sprayed dust inhibitor agents to mitigate spreading of powder dust containing radioactive materials.
Installed a reactor building cover on Unit 1.
Radiation dose at the site was held down due to rubble removal.

  • The removed rubble and waste resulting from restoration work, such as cut down trees due to site cleaning, were transported after they were classified by type and radiation emitting amount at storage site.
  • The rubble was placed in containers and stored indoors in accordance with the radiation emitting amount.

PCV gas control systems were installed at Unit 1,2, and 3.

These strategies have ensured that radiation exposure from the event was minimized so that focus can continue to be on cleanup of the site.


Frequently Asked Questions

Know Nuclear

  • Follow Us
  • Sign up for newsletters
  • Center for Nuclear Science and Technology Information of the American Nuclear Society

    © Copyright 2013