Tokyo Electric Power Co. said Sunday that another reactor of its Fukushima nuclear power plants had lost its cooling functions, Kyodo News reports. The utility supplier notified the government Sunday morning that the No. 3 reactor at the No. 1 Fukushima plant had lost the ability to cool the reactor core. The reactor is now in the process of releasing radioactive steam, top government spokesman Yukio Edano said, according to Kyodo News.