A Japanese man ended up being nicknamed “The World’s Most Radioactive Man” due to a catastrophic example of human error. He never thought that he would stay alive for weeks as his eyes leaked of blood.
The Tokaimura Nuclear Power Plant
Hisashi Ouchi was a 35-year-old power plant technician who worked at the Tokaimura Nuclear Power Plant. He worked alongside Masato Shinohara and Yutaka Yokokawa to convert uranium hexafluoride into enriched uranium. Enriched uranium is vital for nuclear weapons and reactors as it contains a higher percentage of fissile isotopes. During this time, nuclear energy played an important role in Japan’s history due to it’s reliance on imported energy and lack of natural resources.
On September 30, 1999, the three technicians were instructed to figure out a shortcut to fasten the process. Officials missed a deadline on September 28 to generate enough required fuel and promptly needed the enriched uranium. Although the technicians were not trained to handle large amounts of uranium, they used their hands to pour 35 pounds of it into a precipitation tank. They skipped a critical step where they needed to mix the solution with ammonia to complete the “wet process.”
The Fatal Consequences
The tank containing uranium quickly reached critical mass, the smallest amount of fissile material that will keep the nuclear chain reaction constant. A bright blue flash lit up the room and gamma radiation alarms set off. There was no explosion, but the flash confirmed that lethal amounts of radiation were being released from the chain reaction.
The 35-year-old stood directly above the steel tank and was exposed to 17 sieverts. Sieverts are a system of units that represent the health risk of ionizing radiation and seven sieverts are considered fatal. Yokokawa, the only one to survive, endured three sieverts. Shinohara was exposed to 10.
Ouchi’s exposure to the radiation was the largest amount that a human ever suffered. He immediately fainted and began to vomit after regaining consciousness. The National Institute of Radiological Sciences admitted him and observed severe radiation burns, dehydration, and diarrhea. He was transferred to the University of Tokyo Hospital where doctors noticed that the chromosomes in his bone marrow were shattered into pieces and that his immune system was nearly nonexistent.
An End to Ouchi’s Agony
Ouchi’s skin began to fall off and stopped regenerating. He was crying blood and having several cardiac arrests in the span of an hour. The Japanese man was going through agonizing pain and couldn’t even eat. He originally denied a “Do Not Attempt Resuscitation” order, but his family changed their minds after a cardiac event resulted in possible brain damage from unresponsiveness.
Ouchi passed away from multiple organ failure on December 21, 1999. Japan’s Prime Minister at the time expressed his condolences and vowed to increase nuclear safety measures. Shinohara, Ouchi’s coworker, also subsequently passed away in April 2000. More than 160 nearby residents and emergency workers were hospitalized and hundreds of thousands of citizens were directed to stay indoors.
Six officials supervising the Tokaimura Nuclear Power Plant faced charges of negligence resulting in death. Yokokawa, Ouchi and Shinohara’s peer, pleaded guilty to the charges in 2001. The company had to pay $121 million in compensation and the negligence they encouraged led to new legislation in Japan’s nuclear industry.
