A Japanese utility says fuel rods at a troubled nuclear reactor have been fully exposed.
The exposure happened at Unit 2 of the Fukushima Dai-ichi plant -- the latest reactor to lose its ability to cool down. The other two reactors at the plant are facing a meltdown and authorities are racing to cool them with sea water.
Tokyo Electric Power said Monday sea water is being channeled into Unit 2. It did not know if the rods were covered yet.
Their exposure raises the risk of the reactor overheating, which can lead to meltdown.