How often do nuclear power plants go wrong? How many accidents and incidents are there?
The explosions and nuclear fuel rods melting at Japan‘s Fukushima nuclear power plant, following the Sendai earthquake and tsunami last week, have caused fears of what will happen next. So far, the Japanese authorities say there is “no cause to fear a major nuclear accident.”
We have identified 33 serious incidents and accidents at nuclear power stations since the first recorded one in 1952 at Chalk River in Ontario, Canada.
The information is partially from the International Atomic Energy Authority – which, astonishingly, fails to keep a complete historical database – and partially from reports. Of those we have identified, six happened in the US and five in Japan. The UK and Russia have had three apiece.
Using Google Fusion tables, we’ve put these on a map, so you can see how they’re spread around the globe:
But how serious are they? The International Atomic Energy Authority ranks them using a special International Nuclear Events Scale (INES) – ranging from ‘anomaly’ to ‘major accident’, numbered from 1 to 7.
The events at Fukushima are level 4, so far and there has only been one 7 in history: Chernobyl in 1986. You can see the full ranking system below and on the attached spreadsheet
What can you do with the data?
Data summary
Nuclear power station accidents and incidents
Click heading to sort. Download this data
SOURCE: IAEA
2011
Fukushima
4
Japan
Reactor shutdown after the 2011 Sendai earthquake and tsunami; failure of emergency cooling caused an explosion
2011
Onagawa
Japan
Reactor shutdown after the 2011 Sendai earthquake and tsunami caused a fire
2006
Fleurus
4
Belgium
Severe health effects for a worker at a commercial irradiation facility as a result of high doses of radiation
2006
Forsmark
2
Sweden
Degraded safety functions for common cause failure in the emergency power supply system at nuclear power plant
2006
Erwin
US
Thirty-five litres of a highly enriched uranium solution leaked during transfer
2005
Sellafield
3
UK
Release of large quantity of radioactive material, contained within the installation
2005
Atucha
2
Argentina
Overexposure of a worker at a power reactor exceeding the annual limit
2005
Braidwood
US
Nuclear material leak
2003
Paks
3
Hungary
Partially spent fuel rods undergoing cleaning in a tank of heavy water ruptured and spilled fuel pellets
1999
Tokaimura
4
Japan
Fatal overexposures of workers following a criticality event at a nuclear facility
1999
Yanangio
3
Peru
Incident with radiography source resulting in severe radiation burns
1999
Ikitelli
3
Turkey
Loss of a highly radioactive Co-60 source
1999
Ishikawa
2
Japan
Control rod malfunction
1993
Tomsk
4
Russia
Pressure buildup led to an explosive mechanical failure
1993
Cadarache
2
France
Spread of contamination to an area not expected by design
1989
Vandellos
3
Spain
Near accident caused by fire resulting in loss of safety systems at the nuclear power station
1989
Greifswald
Germany
Excessive heating which damaged ten fuel rods
1987
Goiânia
5
Brazil
Four people died and six received doses of a few Gy from an abandoned and ruptured highly radioactive Cs-137 source
1986
Chernobyl
7
Russia
Widespread health and environmental effects. External release of a significant fraction of reactor core inventory
1986
Hamm-Uentrop
Germany
Spherical fuel pebble became lodged in the pipe used to deliver fuel elements to the reactor
1981
Tsuraga
2
Japan
More than 100 workers were exposed to doses of up to 155 millirem per day radiation
1980
Saint Laurent des Eaux
4
France
Melting of one channel of fuel in the reactor with no release outside the site
1979
Three Mile Island
5
US
Severe damage to the reactor core
1977
Jaslovské Bohunice
4
Czechoslovakia
Damaged fuel integrity, extensive corrosion damage of fuel cladding and release of radioactivity
1967
Chapelcross
UK
Graphite debris partially blocked a fuel channel causing a fuel element to melt and catch fire
1966
Monroe
US
Sodium cooling system malfunction
1964
Charlestown
US
Error by a worker at a United Nuclear Corporation fuel facility led to an accidental criticality
1959
Santa Susana Field Laboratory
US
Partial core meltdown
1958
Chalk River
Canada
Due to inadequate cooling a damaged uranium fuel rod caught fire and was torn in two
1958
Vinča
Yugoslavia
During a subcritical counting experiment a power buildup went undetected – six scientists received high doses
1957
Kyshtym
6
Russia
Significant release of radioactive material to the environment from explosion of a high activity waste tank.
1957
Windscale Pile
5
UK
Release of radioactive material to the environment following a fire in a reactor core
1952
Chalk River
5
Canada
A reactor shutoff rod failure, combined with several operator errors, led to a major power excursion of more than double the reactor’s rated output at AECL’s NRX reactor
International Nuclear Events Scale (INES)
Click heading to sort. Download this data
SOURCE: IAEA
7
Major accident
Major release of radio active material with widespread health and environmental effects requiring implementation of planned and extended countermeasures
Chernobyl, Russia, 1986
6
Serious accident
Significant release of radioactive material likely to require implementation of planned countermeasures.
Kyshtym, Russia, 1957
5
Accident with wider consequences
Limited release of radioactive material likely to require implementation of
• Severe damage to reactor core.
Windscale, UK, 1957; Three Mile Island, 1979
some planned countermeasures • Several deaths from radiation
• Release of large quantities of radioactive material within an installation
with a high probability of
significant public exposure. This
could arise from a major criticality accident or fire
4
Accident with local consequences
• Minor release of radioactive material unlikely to result in implementation of planned countermeasures other than
• Fuel melt or damage to fuel resulting in more than 0.1% release of core inventory.
FUKUSHIMA 1, 2011
local food controls.
• Release of significant quantities of radioactive
• At least one death from radiation.
material within an installation with a high probability of significant
public exposure.
3
Serious incident
• Exposure in excess of ten times the statutory annual limit for workers.
• Exposure rates of more than 1 Sv/h in an operating area.
• Near accident at a nuclear power plant
Sellafield, UK, 2005
• Non-lethal deterministic health effect (e.g., burns) from radiation.
• Severe contamination in an area not expected by design, with a
with no safety provisions remaining.
low probability
• Lost or stolen highly radioactive sealed source.
of significant public exposure.
• Misdelivered highly radioactive sealed source without adequate procedures in place to handle it.
2
Incident
• Exposure of a member of the public
• Radiation levels in an operating area
• Significant failures in safety provisions
Atucha, Argentina, 2005
in excess of 10 mSv.
of more than 50 mSv/h.
but with no actual consequences.
• Exposure of a worker in excess of the
• Significant contamination within the
• Found highly radioactive sealed
statutory annual limits
facility into an area not expected by
orphan source, device or transport
design
package with safety provisions intact.
• Inadequate packaging of a highly
radioactive sealed source.
1
Anomaly
• Overexposure of a member of the
public in excess of statutory annual
limits.
• Minor problems with safety
components with significant
defence-in-depth remaining.
• Low activity lost or stolen radioactive
source, device or transport package
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• DATA: download the full spreadsheet
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