Tokaimura Nuclear Accident


Cooler King
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In September 1999, three workers were exposed to extremely high levels of radiation at a uranium conversion plant in Tokaimura (70 miles from Tokyo) and 150 others were exposed to dangerous levels of radiation. One of the workers died in December, 1999. Another worker died in April 2000. It was the worst nuclear accident in Japan's history at that time.

The accident occurred when workers at the plant accidently poured too much of a uranium-235 solution—35.2 pounds instead of the required 5.2 pounds—into stainless steel buckets with nitric acid in them. The workers were mixing the radioactive materials by hand to save time and money. The first sign that something had gone wrong was a flash of blue light that caused one worker to fall unconscious and another to become nauseous and experience burns.

The workers were making a fuel for a breeder-type reactor, which is supposed to be done slowly and carefully. Instead the uranium was dumped in all at once and went critical (a sustained chain reaction) for 18 hours before it was contained, releasing large amounts of radiation, some of which threatened 300,000 people in the Tokaimura area.

NUCLEAR ENERGY IN JAPAN - Japan | Facts and Details

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