Hazard sign indicating radiation is seen in front of a containment shelter for the damaged fourth reactor...
A hazard sign indicating radiation is seen in front of a containment shelter for the damaged fourth reactor at the Chernobyl nuclear power plant April 24, 2012. Belarus, Ukraine and Russia mark the 26th anniversary of the Chernobyl disaster, the world's worst civil nuclear accident, on Thursday. REUTERS/Gleb Garanich (UKRAINE - Tags: DISASTER ENERGY ANNIVERSARY)