A quake-hit Japanese city called in the head of Asia's biggest utility today and ordered him to keep a nuclear plant closed until safety could be ensured after the tremor caused minor radiation leaks.
Tokyo Electric Power Co (Tepco) said Monday's 6.8 magnitude quake caused 50 problems at its Kashiwazaki-Kariwa plant in northwest Japan, including emission of a small amount of radioactive material into the atmosphere.
The leaks renewed fears over safety in Japan's nuclear industry, whose image has been tarnished by scandals over cover-ups and fudged safety records.
About 1,200 litres of radioactive water also leaked into the sea from a reactor at the world's biggest nuclear plant, and a fire erupted in an electricity transformer.
"I apologise for causing you worry and trouble," Tepco president Tsunehisa Katsumata, dressed in blue overalls, told Hiroshi Aida, mayor of the city worst hit in the tremor.
Nine elderly people died and more than 1,100 were injured in the tremor. It flattened hundreds of homes, and thousands of people are staying in evacuation centres.
"I think we can say the size of the earthquake was beyond our expectations," Mr Katsumata said.
The company said reactors closed down automatically in the quake and all emissions were well within government safety guidelines, presenting no threat to the environment, but local people voiced unease.
"We've had two big ones in three years," said Hoshi Murofushi (60), who was sheltering with her two grandchildren in an evacuation centre in Kariwa. "There's no guarantee that there won't be another one. It will be too late if we have another Chernobyl."
Senior officials including Prime Minister Shinzo Abe criticised Tepco, saying it had been slow to issue information and risked undermining public trust in the nuclear industry.
Quake proofing regulations for nuclear power stations were stepped up last year, requiring power companies to re-assess the risks for their reactors.