The AP is reporting that a radiation leak has affected numerous people in the Hadron Experimental Facility at the Japan Proton Accelerator Research Complex in the town of Tokaimura.
Up to 55 people were affected, with at least “six researchers suffering internal radiation exposure.”
The report indicates that “researchers were trying to generate particles by directing a proton beam at some gold when their equipment overheated, causing the evaporation and release of radioactive gold.”
The leak took place on May 23, but was not reported because it was thought to have been contained within the lab. However, once a ventilator was turned on it spread throughout the facility, and it was after this–on May 24–that the leak was reported.
Researches said the vent was turned on because they believed the radioactive substances would “quickly decay.” An investigation has now been launched to see if there were ulterior reasons for not reporting the leak quickly.
For now, all work at the Hadron Experimental Facility has been suspended.