Six days after the earthquake that rocked Japan and left thousands dead, the nation is now struggling to avert disaster at its Fukushima Daiichi nuclear power plant. Events have moved fast and risks are hard to assess.
The worst nuclear accident in history was the Chernobyl explosion of 1986 in what is now Ukraine. Nuclear experts have repeatedly stated that the Japanese situation cannot get as bad as Chernobyl. New Scientist explains why.