You would think 3 months after the disaster that they would have installed new back-up generators for a scenario such as this.
From Kyodo:
The crisis-hit Fukushima Daiichi nuclear power plant suffered power outages at its Nos. 1 and 2 reactors Wednesday, with lights cut off in the units' central control room, and water level and pressure indictors for one of the reactors out of service for more than three hours.
The plant's operator, Tokyo Electric Power Co., said the blackout did not affect its water injection operation to prevent the crisis from worsening and no evidence of abnormalities was found in data on the No. 2 reactor after power was restored in the evening, but the government urged the utility again to diversify power sources at the six-reactor complex.
The power outage occurred around 2:20 p.m. and electricity began to be restored around 5:30 p.m., the utility known as TEPCO said, adding that it is investigating the cause of the incident.
