On September 30, 1999, 35-year-old Hisashi Ouchi was working at a nuclear fuel plant in Tokaimura, Japan, when a blue flash changed his life forever. He and two other workers were mixing uranium oxide to make fuel rods for a research reactor. They were supposed to use an automatic pump to mix small amounts of uranium with nitric acid. Instead, they used steel buckets and poured in 16 kilograms of uranium. That was about seven times more than the safe limit.
The extra uranium reached a critical point at 10:35 in the morning. This started an out of control nuclear reaction that released huge amounts of radiation for almost 20 hours. Ouchi was standing closest to the tank when it happened. He got hit with 17 sieverts of radiation. His coworker Masato Shinohara got 10 sieverts and their boss Yutaka Yokokawa got 3 sieverts. Doctors say anything above 7 sieverts will kill you. Ouchi was taken to the University of Tokyo Hospital where doctors found he had almost no white blood cells left.
