The greatest nuclear disaster ever happened 31 years ago on 26 April 1986 in Chernobyl- Ukraine. Reactor 4 exploded with a power 10 times bigger than the bomb on Hiroshima. Pripyat a young city with 50.000 inhabitants build in 1970 for people who worked in Chernobyl and their family was evacuated in 48 hours. Many people died whitin a few months after the explosion, the number of deadly victims who died years later caused by radiation is not clear but are several thousands. Radioactivity will slowly decrease but the area is radioactive infected for minimal 500 years. Since the disaster the city is abandoned and nature is taking it over slowly.