Overview
- Reports recount that coworkers mistakenly added excessive uranium to a processing tank on September 30, 1999, triggering an uncontrolled chain reaction.
- Standing nearest the vessel, Hisashi Ouchi was estimated to have received 17,000 millisieverts of radiation, described as the highest documented human dose.
- He endured 83 days of intensive, largely experimental care at the University of Tokyo Hospital and died on December 21, 1999 of multiple organ failure.
- Accounts describe his reported plea to staff—“I can’t take it anymore. I am not a guinea pig.”—as doctors maintained life support and administered up to ten daily transfusions.
- A government probe blamed absent oversight, poor safety culture, and inadequate training; six company officials were charged and received suspended sentences in 2003, while coworker Shinohara died in April 2000 and supervisor Yokokawa survived.