Civilian Nuclear Accidents

Since the discovery of plutonium and its use for nuclear weapons and nuclear energy radionuclides have been dispersed into the environment and contribute significantly to the global presence of anthropogenic radionuclides. Today, nuclear power plants are controlled by the national radiation protection authorities but are continuously emitting the small amounts of radioactivity permitted by the national health authorities. Other releases originate from the use of radionuclides in medical diagnostic and therapeutic treatments. Although these releases are minor compared to natural radioactivity and anthropogenic radionuclides, they contribute to the current radiation background. The anthropogenic actinides in the northern hemisphere mainly originated during nuclear weapons testing, fallout from the reactor accident at Chernobyl, atmospheric burnup of nuclear satellites, and intentional discharges of liquid waste streams from industrial-scale nuclear reprocessing facilities. Despite the increasingly sophisticated engineered reactor and processing systems, accidents since the 1950s have resulted in the release of radioactivity to the environment. The most prominent accidents that led to a significant dispersion of radionuclides are the Three Miles Island accident, the Windscale Fire, and the Chernobyl accident. In this article, we discuss these events and other nonweapons related uncontrolled releases of radioactivity into the environment. Keywords: nuclear accident; Chernobyl; Three Mile Island; Windscale; processing; environment