The use of nuclear energy has given rise to concern over safety. Anxiety has been heightened by accidents such as those at Windscale (UK), Three Mile Island (US), and Chernobyl (Ukraine).
There has also been mounting concern about the production and disposal of nuclear waste, the radioactive and toxic by-products of the nuclear energy industry. Burial on land or at sea raises problems of safety, environmental pollution, and security. Nuclear waste has an active half-life of thousands of years and no guarantees exist for the safety of the various methods of disposal.
Nuclear safety is still a controversial subject since governments will not recognize the hazards of radiation and radiation sickness. In 1990 a scientific study revealed an increased risk of leukemia in children whose fathers had worked at Sellafield between 1950 and 1985. Sellafield (UK) is the world's greatest discharger of radioactive waste, followed by Hanford, Washington (US).