In this March 11, 2011 photo released by Tokyo Electric Power Co., tsunami waves approach tanks of heavy oil for the Unit 5 reactor of the Fukushima Dai-ichi nuclear complex in Okuma, Fukushima Prefecture, (AP).
Japan said Wednesday it will conduct "stress tests" on all the country's nuclear plants to ease heightened concerns about disaster preparedness after this year's tsunami sparked the worst nuclear crisis since Chernobyl.
The March 11 earthquake and tsunami in northeastern Japan knocked out power at the Fukushima Dai-ichi plant, sending it toward meltdown in a crisis that engineers are still struggling to contain. The plant operator has come under heavy criticism for failing to sufficiently prepare for the disasters.
The government already ordered exhaustive safety checks on all the country's 54 nuclear reactors following the disaster, and it was not immediately clear what additional measures would be added by the stress tests.
Officials provided few details. However, Minister of Economy, Trade and Industry Banri Kaieda said the new safety checks will gauge the facilities' defenses against extreme events like big earthquakes.
"There is no change in our view that it is safe," Kaieda said, adding that the tests are intended to offer more reassurance to local residents.
More than two-thirds of Japan's reactors remain offline. Utilities with plants that were shut down for safety reviews after the crisis or that already had been offline due to routine maintenance have been reluctant to restart them because of public anxiety and anti-nuclear protests.
A major on the southwest island of Kyushu last week endorsed the resumption of operations at two nuclear reactors in his city, Genkai, in what would be the first restart of idled plants since the Fukushima crisis. But the latest announcement is likely to delay that process.
The governor of Saga prefecture, where Genkai is located, has yet to add his own approval. He said Wednesday that he would hold off on making a final decision until results of the new test became available, according to Kyodo News agency.
Kaieda said Japan's stress tests will incorporate elements from those ordered by the European Union on the 143 nuclear plants in that region after the Fukushima crisis.
Those reviews, which started June 1, are supposed to consider the impact of both natural and man-made events such as airplane crashes and terrorist attacks.
Kaieda said Japan's stress tests also will include ideas from Japanese regulators and local residents.
Nuclear power generates about 30 percent of Japan's electricity. If nuclear reactors currently shut for maintenance face delays in resuming operations, the country could face a power shortfall in the months ahead. But Kaieda played down such worries.
"I will take responsibility to ensure that there are no power supply problems," he said.