World’s worst nuclear disaster leaves mixed legacy of nature’s resilience amid serious contamination, as wars increase lobbying for energy supply World’s worst nuclear disaster leaves mixed legacy of nature’s resilience amid serious contamination, as wars increase lobbying for energy supply F orty years on from the world’s worst nuclear disaster, Chornobyl is still contaminated with almost half the caesium-137 that exploded from the Unit 4 reactor in 1986, as well as much longer-lived hazards