The release of radioactive material from a Japan Atomic Energy Agency facility in Tokai, Ibaraki Prefecture, last week suggests scientists still lack a sense of crisis and urgency about radiation dangers despite the 2011 Fukushima disaster.

At least 30 researchers at the Hadron Experimental Facility of the Japan Proton Accelerator Research Complex (J-PARC) sustained internal radiation exposure in Thursday's accident.

An alarm went off at 11:55 a.m. Thursday in a radiation-controlled part of the Hadron facility when an experiment to generate elementary particles by aiming a proton beam at a target made of gold went haywire. After halting the experiment for the alarm, a researcher in charge decided there was no danger and restarted the equipment just 13 minutes later.