(FILES) Picture taken from a helicopter in April 1986 shows a general view of the destroyed 4th power block of Chernobyl`s nuclear power plant few days after the catastrophe. A reactor at Chernobyl blew up on April 26, 1986 in the worst nuclear accident in history. Ukraine will on April 30, 2026 mark the 40th anniversary of the Chernobyl accident, the worst civilian nuclear disaster in history. The risks of new radioactive releases still remain today, as the site is threatened by Russian strikes after it invaded the neighbour four years ago. (Photo by VLADIMIR REPIK / AFP)