TOKYO – A major aftershock rocked northeast Japan late yesterday and a wave warning was issued for the coast devastated by last month’s massive quake and tsunami that crippled a nuclear power plant.
That warning was later lifted and no damage from the quake, measured at magnitude 7.4 by the Japan Meteorological Agency, was detected at the Fukushima Daiichi plant, operator Tokyo Electric Power Co (Tepco) said.
Workers struggling to bring the plant under control were evacuated after the aftershock struck.
Large parts of northern Japan, where infrastructure was severely damaged by the March 11th quake and tsunami, were without electricity following the latest of many aftershocks, the biggest since last month’s devastating quake.
In Tokyo, buildings shook. “It started out as nothing much, then the building started swaying quite strongly,” one witness said.
NHK public television cited police as saying seven people had been injured, two of them seriously.
Last month’s disaster has disrupted industry and affected supply chains around the world. But it was not immediately clear if the aftershock would compound those problems.
At the Fukushima nuclear plant, Tepco said it was continuing to inject nitrogen into reactor No 1 after no irregularities were reported.
Engineers who sealed a leak this week that had allowed highly radioactive water into the sea are pumping nitrogen into one reactor to prevent the risk of a hydrogen gas explosion. They want to start the process in another two reactors.
There were no abnormalities in radiation levels around Tohoku Electric’s Onagawa nuclear power plant, where fuel rods are being cooled with just one outside power source, Japan’s nuclear safety agency said.
As well as Fukushima Daiichi and Onagawa, nuclear power plants Higashidori in Aomori prefecture, Tokai No 2 in Ibaraki prefecture and Fukushima Daini have been out of operation since the March quake.
No abnormalities were reported at those plants after the late evening quake, which the meteorological agency said was an aftershock from last months magnitude 9.0 quake.
About 28,000 people were killed or are missing as a consequence of the March earthquake.
Japan’s neighbours have sounded increasingly alarmed over the risk of radiation from the plant while tourists are staying away in what should be the peak season. The country is also seeking ways to reduce demand for power.
The world’s worst nuclear disaster in 25 years is also raising concern over safety in the United States which has more atomic reactors than any other country, especially at one plant which is similar to the Fukushima facility.
Tepco also indicated that it did not expect it would have to dump any more contaminated water into the ocean after Saturday.
Earlier, the Tokyo company said the chance of a repeat of the gas explosions that damaged two reactors in the first days of the disaster was “extremely small”.
But as engineers battle multiple crises – some the result of efforts to try to cool reactors – officials admit it could take months to bring the reactors under control and years to clear up the toxic mess left behind at the plant 240km (150 miles) north of Tokyo.
“Data shows the reactors are in a stable condition, but we are not out of the woods yet,” chief cabinet secretary Yukio Edano said.
The government has already set up a 20km (12 miles) exclusion zone around the plant, banned fishing along much of the northeast coast and set up evacuation centres for the tens of thousands forced to leave their homes.
Traces of radioactive material have been detected in 22 Chinese provinces but the amounts did not pose a threat, China’s Xinhua newsagency said. – (Reuters)