KAWAUCHI, Japan — Several hundred residents forced out by the Fukushima nuclear meltdown have made a nervous first return to their homes here in Kawauchi. Radiation, while still elevated, has dropped to levels Japan considers safe. A handful of children were welcomed back to school with an emotional ceremony, and the mayor praised their courage. "You have had a tough time as refugees, but now you can concentrate on the things that matter, like school and home," he said. Many others, however, remain unconvinced that the village is safe.