Chernobyl: 40 years on from the world's most devastating nuclear disaster

April 26 marks the 40th anniversary of the Chernobyl disaster, still considered the world's worst nuclear accident. In 1986, a safety test at reactor number four in Soviet-controlled Ukraine went terribly wrong, causing an explosion and the largest-ever release of radioactive material into the environment. Over 3.5 million people were affected, nearly 50,000 square kilometres of land contaminated, and the harmful fallout spread across Europe, including Britain. Thirty died immediately, 350,000 were evacuated, and 5,000 children developed thyroid cancer. Investigations blamed poor plant design and inadequately trained staff. The disaster's devastating impact was retold in the acclaimed mini-series 'Chernobyl', highlighting the key individuals at the tragedy's heart and the enormous efforts made to contain the catastrophe.