Comparative Risk Review of Major Nuclear Disasters: Analyzing Radiation Exposure, Environmental Impact and Health Consequences Across the Worst Accidents

Nuclear disasters have had profound and lasting effects on human health, the environment, and energy policies worldwide. This systematic review examined five major nuclear accidents: Kyshtym (1957), Windscale (1957), Three Mile Island (1979), Chernobyl (1986), and Fukushima (2011)—to analyze their radiation exposure, environmental impact, and health consequences. Using peer-reviewed literature from 2010 to 2025, the study evaluates the severity of radioactive releases, the isotopes involved, affected populations, and decontamination measures implemented. The results indicated significant variations in the magnitude of radioactive emissions, with Chernobyl releasing the highest radiation (5,300 PBq), leading to widespread contamination and long-term health effects, including over 6,000 thyroid cancer cases. Fukushima, despite being classified as a Level 7 event, had a much lower radiation release (520 PBq) but caused severe psychological distress and displacement of thousands of residents. Windscale and Three Mile Island, though lower in severity, had critical implications for nuclear policies and public perception. The study also explores the long-term environmental consequences of these disasters, including soil and water contamination, bioaccumulation of radioactive isotopes, and ecosystem disruptions. Decontamination efforts varied, with strategies ranging from reactor containment and topsoil removal to advanced filtration techniques. The review highlights key lessons in nuclear safety, including the role of human error, inadequate reactor designs, and the effectiveness of emergency response protocols. Findings underscore the necessity of stricter safety regulations, improved reactor technologies, and sustainable energy alternatives to minimize the risks associated with nuclear power. Understanding past disasters is crucial in preventing future nuclear crises and ensuring a more resilient approach to energy production and disaster preparedness.