Radiation Safety

Accelerator Leak Halts Japanese Physics Experiments

A beam malfunction at the Japan Proton Accelerator Research Complex (J-PARC) in Tokai, Japan, on 23 May released radioactive material into an experimental hall. Operators then vented the hall, contaminating the environment. The J-PARC facility has been shut down for an investigation. The amount of radiation involved was small (the two most exposed workers received doses of about 1.7 millisieverts, equivalent to a high-dose medical x-ray). But the handling of the accident raises new questions about safety procedures in a nation still nervous about radiation following the 2011 Fukushima nuclear power plant disaster.

  • * With reporting by Adrian Cho.