Japan's nuclear regulation body decided Wednesday to review the nation's distribution system for iodine tablets against radiation exposure, with an eye on giving priority to children.

Current rules say iodine tablets should be in principle distributed in advance to all residents living within a 5-kilometer radius of 16 nuclear plants in 13 prefectures, where doing so is deemed difficult in emergency situations.

But some municipal governments have yet to hand out the tablets to all residents, including children who are more vulnerable to radiation exposure.