Tokaimura Tragedy – History’s Worst Criticality Accident

From Kyle Hill. On September 30, 1999, the Tokaimura nuclear accident became the worst criticality accident in modern nuclear history. At a uranium processing facility in Japan, workers accidentally triggered a self-sustaining nuclear reaction while preparing fuel for an experimental reactor. One of the technicians, Hisashi Ouchi, received a massive radiation dose and spent 83…

Tokaimura Tragedy – History’s Worst Criticality Accident

From Kyle Hill. On September 30, 1999, the Tokaimura nuclear accident became the worst criticality accident in modern nuclear history. At a uranium processing facility in Japan, workers accidentally triggered a self-sustaining nuclear reaction while preparing fuel for an experimental reactor. One of the technicians, Hisashi Ouchi, received a massive radiation dose and spent 83…