TOKYO (AP) - Four fuel storage pools at Japan's tsunami-damaged nuclear plant have been without fresh cooling water for more than 15 hours due to a power outage.
The plant's operator said on Tuesday morning that it was trying to repair a broken switchboard that might the cause of the problem.
Tokyo Electric Power Co. said that pool temperatures were well within safe levels at the Fukushima Dai-ichi plant and that pools would remain safe for four days without fresh water.
Tokyo Electric Power Co. official Masayuki Ono said the utility was preparing a backup system in case the repairs did not work.
A 2011 earthquake and tsunami destroyed the plant's power and cooling systems, causing three reactor cores to melt and fuel storage pools to overheat. It is now using makeshift systems.