The incident took place in a conversion building operated by JCO (formerly Japan Nuclear Fuel Conversion Co.) a subsidiary of Sumitomo Metal Mining Company in the village of Tōkai. It was essentially an 'irradiation' accident, not a 'contamination' accident, as it did not result in any significant release of radioactive materials. [17] The company had not had any incidents for over 15 years making company employees complacent in their daily responsibilities. However, this was to be limited to one billion yen, with further liability (the total estimated at 13 billion yen) being met by JCO or its parent company. Tokaimura nuclear accident JCO worker succumbs after 83 days. He and another worker who was near the sink immediately experienced pain [19] The buffer tank's tall, narrow geometry was designed to hold the solution safely and to prevent criticality. Health checks conducted on all residents measuring radiation, schools reopened and government press conferences held, International Atomic Energy Agency: “Report on the preliminary fact finding mission following the accident at the nuclear fuel processing facility in Tokaimura, Japan”, 1999, This page was last edited on 13 April 2021, at 19:16. Furthermore, a widely distributed but unauthorized 1996 manual recommended the use of buckets in making the solution. [5] Originally, the Tokaimura plant was established as a small-scale fuel preparation plant and not associated with electricity production or manufacturing operation routines. Three Mile Island, USA, 1979 (fuel melting). [7] In order to produce the necessary uranium fuel, a purified chemical procedure with three crucial steps is required. Only trace levels of radionuclides were detected in the area soon after the accident, and these were short-lived ones. (To see both the Japanese transcript and the English translation, click here.) Three (in 1958 and 1964) were very similar to this accident. PNC leadership claimed normal levels of radioactivity in the area the morning of 13 March. Dōnen facility officials initially reported a 20 percent increase of radiation levels in the area surrounding the reprocessing plant but later revealed the true percent was ten times higher than initially published. Despite their efforts, his condition deteriorated into multiple organ failure resulting from extensive radiation damage, exacerbated by the repeated incidents where Ouchi's heart stopped. [17], Efforts to comply with emergency preparedness procedures and international guideline requirements continued. [17] These inspections focused on the proper conduct of workers and leadership. The next task was to install shielding to protect people outside the building from gamma radiation from the fission products in the tank. The criticality continued intermittently for about 20 hours. The nuclear fuel conversion standards specified in the 1996 JCO Operating Manual dictated the proper procedures regarding dissolution of uranium oxide powder in a designated dissolution tank. Five hours after the start of the criticality, evacuation commenced of some 161 people from 39 households within a 350 metre radius from the conversion building. [3] This event contributed to antinuclear activist movements against production of nuclear energy in Japan. [8] Next, the mixture is carefully transported to a specially-crafted buffer tank. The Cali Explosion occurred on August 7, 1956 in downtown Cali, Colombia. The energy released in the similar US accident was about 3 MJ, though due to the prolonged criticality here, some 80 MJ was released, equivalent to the combustion of just over two litres of petrol/gasoline. Neighboring power plants the public, it is one of the facility were told to stay indoors and all... 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