Nuclear Meltdowns: Risks, History, and Safety

Environmentalists tend to denounce nuclear power as much too risky, with grave consequences for a meltdown. Nuclear utilities and advocates claim a good, if not perfect, safety record. While nuclear plant designs have improved, they will never be risk-free.

Historical Meltdowns

• Commercial nuclear sites have experienced one meltdown and three partial meltdowns: Three Mile Island, Chernobyl, Chalk River and Lubmin. A few experimental reactors have also had partial meltdowns. If designs, human factors and number of plants remained the same, you could put the risk for meltdown at about one every 10 years.

Plant Design

• The chances of a nuclear power plant meltdown vary with plant design and maintenance level. Newer designs incorporate safety features developed from past problems. Proponents for reactors such as the Integral Fast Reactor (IFR), claim that they can't melt down. The world still has a number of older reactors still operating, however, keeping risks higher.

Human Factors

• Risks for meltdown also vary with the condition of the people running the plant. Problems with human factors, such as worker fatigue and confusion, contributed to the Three Mile Island and Chernobyl accidents.