TEPCO achieves cold shutdown of stricken Fukushima plant
Prime Minister Yoshihiko Noda of Japan on Friday declared the damaged reactors at the Fukushima Daiichi nuclear power plant have been brought to a state of cold shutdown, turning a corner in the world's worst nuclear disaster since Chernobyl.
"The nuclear reactors have reached a state of cold shutdown and therefore we can now confirm that we have come to the end of the accident phase of the actual reactors," Prime Minister Noda told a news conference.
The cold shutdown state - when water used to cool nuclear fuel rods remains below boiling point so the fuel cannot reheat - is a target in the second phase of a timetable established by the government and the plant's owner-operator Tokyo Electric Power Company to bring the crippled facility under control.
TEPCO said that cold shutdown means the plant is "stabilized in case an accident occurs, we will be able to keep the radiation dose at the site boundary at a sufficiently low level," not exceeding one milliseivert per year.
Prime Minister Noda said, "We can now maintain radiation exposure at the periphery of the plant at sufficiently low levels even in the event of another accident."
Many challenges remain, Noda said, including decontamination work in no-entry zones and government-designated evacuation zones around the plant and the return of thousands of evacuees to their homes.
More than 80,000 people were evacuated after the accident; many are still living in shelters. A 20 kilometer exclusion zone remains in place around the nuclear plant.