Border of the Fukushima exclusion zone. Credit: GaijinSeb/Flickr/CC

Last year, on March 11, a deadly earthquake and tsunami rocked Japan , killing more than 15,000 people. To make matters worse, the natural disaster triggered a major crisis at the Fukushima Daiichi nuclear power station. The subsequent meltdown and radioactive release is the only event in history other than Chernobyl to rate as a major accident on an international scale of nuclear severity. Fukushima is not expected to cause as many deaths as Chernobyl, but contamination from the accident is widespread and will be long-lived. One year after the nuclear crisis began, an exclusion zone 20 kilometers in radius remains in place around the reactors.