Chernobyl: 26 years on
Chernobyl was the first, and until Fukushima, only major nuclear accident to reach Level 7 on the 7-point International Nuclear Events scale (INES).
Despite efforts by the International Atomic Energy Agency to play down the disaster as a one-off resulting from poor work practices in the former Soviet Union, the world today is contemplating the ruins of a second reactor complex on Japan's Pacific Coast.