Nuclear labor issues the most dangerous tasks within the industry is intensified by nuclear secrecy. On May 22, 1986, a nuclear fuel reprocessing plant at La Hague in Normandy, sustained a mechanical malfunction. Five workers were exposed to unsafe levels of radiation and hospitalized. On April 12, 1987, the Tricastin Nuclear Power Plant fast breeder reactor coolant leaked contaminating seven workers. In July 2008, approximately 100 workers were exposed to a radiation leak. The Chernobyl nuclear reactor meltdown occurred on April 26, 1986, in the Ukraine, during a test of the Unit 4 reactor systems. The explosion and fire caused by human error
Peaceful nuclear explosion many of the "tests" were considered economic applications, not tests, in the Nuclear Explosions for the National Economy program. These included one 30 kiloton explosion being used to close the Uzbekistani "Urtabulak" gas well in 1966 that had been blowing since 1963, and a few months later a 47 kiloton explosive was used to seal a higher pressure blowout at the nearby "Pamuk" gas field. (For more details, see Blowout (well drilling)#Use of nuclear explosions.) The public records for devices that produced the highest proportion of their yield via fusion-only reactions are possibly the Taiga Soviet peaceful nuclear explosions of