Accidents

Chapter overview

So there are a few factors in everyone's mind when it comes to nuclear power. Admist all the talk about how safe reactors really are, there will always be doubt in people's minds about safety as long as certain notable accidents are addressed. This chapter addresses the big ones in nuclear history and shows why it is that those should not make us fear nuclear power today.

Chernobyl
Unquestionably the most prominent and catastrophic accident in the history of nuclear power. Much emotion and hyperbole surrounds it and reference to it has become a sort of Hail Mary for the nuclear opposition. This page gets beyond the hype and discusses the real causes and consequences of this disaster and what it tells us about nuclear power today.
Three Mile Island
Many credit the Three Mile Island meltdown with destroying the nuclear industry in the United States. Though not the sole cause it was certainly the very large straw. It was in fact the biggest panic attack in history. This page discusses the fallout from this accident.
Tokaimura
Tokaimura goes down in a very long list of accidents at chemical processing plants caused by disrespect for the dangers of working with hazardous material. This page discusses what went wrong and the consequences of the accident.
Browns Ferry
In many ways, Browns Ferry is considered to be the prequel to Three Mile Island. Despite the fact that it never reached the status of nuclear accident like TMI, it still taught engineers some valuable lessons that have shaped reactor design today. This page discusses why Browns Ferry is not a reason to fear nuclear power.
Other accidents
This is a log of some of other less significant accidents and incidents that have happened in the nuclear industry, and naturally, have been blown out of all proportion by the sensation hungry media and alarmists.

The IAEA has defined a simple system of grading the severity of any nuclear accident, malfunction or anomaly. It assigns a level of severity from 0 to 7 based on the following standards:

Level Description Impact Example
7 Major accident Total loss of containment leading to major release with extended health and environmental effects. Chernobyl (1986)
6 Serious accident Loss of containment leading to signifincant release with full implementation of local emergency procedures. Mayak (1957)
5 Accident with off-site risks Severe core damage
or
possibly with limited release leading to partial implementation of emergency plans.
Three Mile Island (1979), Windscale (1957)
4 Accident mainly on-site Either minor release at regulation limiting levels
or
partial core damage or severe harm, possibly fatality, to workers.
Saint-Laurent (1980), Tokaimura (1996)
3 Serious incident Either insignificant release below regulation limiting levels
or
contamination and overexposure of workers of less significant effect
or
near accident with severe loss of defence-in-depth layers.
Sellafield-THORP (2005), Davis-Besse (2002)
2 Incident Contamination strictly on-site
or
overexposure of workers with little harm
or
failure of safety equipment.
Forsmark (2006)
1 Anomaly Departure from regulation operating parameters.  
0 Below scale Anomaly of no safety significance