Blackout interrupts cooling at Fukushima Daiichi

 NHK

Tokyo Electric Power Company officials say a power blackout caused a malfunction in the cooling system for spent nuclear fuel at the struggling Fukushima Daiichi power plant.

A TEPCO spokesperson said the blackout occurred shortly before 7 PM on Monday.

It disrupted cooling at the plant's number 1, 3 and 4 reactors.

Officials say they recorded temperatures of up to 25 degree Celsius in the pools at 6 PM Monday.

They say it will take about 4 days for the hottest pool to exceed the safety limit of 65 degrees Celsius.

They say the blackout has interrupted the cooling system for another pool containing used fuel.

TEPCO officials say about 8,500 spent fuel units are stored in the 4 pools.

They say the power outage has not prevented the injection of coolant into the crippled reactors.

They also say they have observed no change in radiation levels at monitoring posts around Fukushima Daiichi.

Workers will begin restoring the cooling system once they discover the cause of the interruption.

TEPCO officials took 3 hours to announce the incident. They have apologized for the delay and said they were double checking the situation at the facility.

It's not the first time the plant has experienced electrical problems. The cooling system for 3 pools broke down for an hour in January 2012.

Last June, a pump to circulate water in the spent-fuel pool of the number 4 reactor malfunctioned and halted the cooling process for about 30 hours.