Tokyo Electric Power's (Tepco) Fukushima power plants were thrust back into the spotlight on Tuesday, after an earthquake hit the region, reviving memories of 2011's tragic nuclear disaster.
A 7.4 magnitude quake shook the coast of Fukushima at about 6 a.m. local time, producing a tsunami with 3-meter high waves on the northern Pacific coast, Japan's Meteorological Agency (JMA) said. American quake monitoring agency USGS later downgraded the magnitude to 6.9, from its initial measure of 7.3, and tsunami warnings were lifted by 12.50 p.m. local time.
Tuesday's quake was actually an aftershock of the 9.1 magnitude earthquake in 2011 that hit the same region, according to the JMA. Back then, the deadly quake and subsequent tsunami destroyed the cooling system at Tepco's Daiichi nuclear plant, resulting in a massive meltdown and the release of radioactive material that continues to contaminate the area.
Following Tuesday's quake, Tepco's Daini plant—separate from the Daiichi unit—said that a system designed to keep atomic fuel cool at one reactor was halted. But after around 90 minutes, Tepco announced that it had restarted the cooling system. Even when plants are shut, fuel needs to be kept cool to prevent overheating, which could lead to meltdown, as occurred in 2011.
Experts were quick to praise the firm's quick technical response and communication.
"Tecpco did much better this time than in 2011...As someone who is chairing their reform committee, I always want them to improve but they did well today," remarked Dale Klein, associate vice chancellor for research at the University of Texas System.
For the past five years, all of Tepco's plants in Fukushima have remained shut since and no problems were announced at other plants on Tuesday.