The nuclear disaster that occurred in 1986 was the Chernobyl disaster. It took place on April 26, 1986, at the Chernobyl Nuclear Power Plant in Ukraine, then part of the Soviet Union. A reactor explosion released significant amounts of radioactive particles into the atmosphere, leading to widespread contamination and affecting large areas in Europe. It is considered one of the worst nuclear disasters in history, resulting in health issues, environmental damage, and the evacuation of thousands of people from surrounding areas. The incident highlighted the dangers of nuclear power and led to major changes in safety standards and regulations in the industry.