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September thirtieth
A melt down caused by bringing together too much uranium enriched to a relatively high level, causing a 'criticality' (a limited uncontrolled nuclear chain reaction), which continued intermittently for 20 hours .A total of 119 people received a radiation dose over 1 mSv from the accident, but only the three operators' doses were above permissible limits. Two of the doses proved fatal. -
Period: to
Tokaimura Nuclear Accident
A nuclear core meltdown on September 30, 1999, caused over 10 casualties -
October first
More than 310,000 people were ordered not to leave their homes and officials shut down schools and train service in the region.
The government asked US military forces in Japan for help, but were told that the US forces there were not equipped to handle such accidents. The government task force composed of top ministers sent specialists to the area to monitor the radioactivity. -
October Second
News that there is no health threat outside Japan from radiation. Three workers were said to be exposed to the radiation a lot. And the people around got angry that the nuclear accident was not a big threat to them. -
October third
Police investigated allegations of negligence at the plant. They are intended to lay criminal charges on the company. -
October fourth
Six of the eighteen workers who suffered radiation exposure while trying to remove coolant water from the plant's pipes were exposed to a level above the annual limit set by law. The five others who suffered radiation exposure above the limit were exposed to about 56 to 73 millisieverts each, while four others were exposed to more than 40 millisievert. -
November twenty-ninth
This when discussion about safety and how this effected the economy. -
December fourteenth
The Japanese Diet enacted two bills designed to empower the national government in dealing with nuclear accidents. One of the new laws stipulates that the prime minister becomes the head of a national headquarters to deal with situations when nuclear accidents of a serious nature take place. Another law provides that nuclear-fuel facilities should be inspected periodically and training should be given to employees of those facilities. -
December twenty-three
Investigators have found more workers have died because of the accident. -
December twenty-fourth
The report does not analyze the circumstances under which workers at the uranium processing plant had come to use procedures that deviated from government regulations. Nor does it include a final count of plant employees and residents near the facility who were irradiated in the accident. Some observers believe the report deliberately omitted the final count of accident victims to avoid the "bad timing" following Ouchi's death. -
January 1
Including workers inside the plant run by JCO Co., a total of 439 people were exposed to radiation. However, the agency said that except for the three JCO workers whose actions triggered the accident, none of the 439 were exposed to 50 millisieverts or more of radiation, ruling out the possibility of related health problems, such as cancer. Also exposed to radiation were 57 officials from the Japan Atomic Energy Research Institute. -
February eleventh
There have been new standards and regulations added for nuclear accidents to prevent further accidents.