Japan's prime minister has announced that the tsunami-devastated Fukushima Dai-ichi nuclear power plant has reached a "cold shutdown" and is no longer leaking substantial amounts of radiation.
Yoshihiko Noda's announcement marks a milestone nine months after the March 11 tsunami sent three reactors at the plant into meltdowns in the worst nuclear crisis since Chernobyl.
But experts noted that the plant remains vulnerable to more problems and will take decades to decommission.
The crisis displaced some 100,000 people. Officials are to start discussing allowing some residents to return to less contaminated areas.
A 12-mile zone around the plant is expected to remain mostly off-limits for years.
"The reactors at the Fukushima Dai-ichi nuclear power plant have reached a state of cold shutdown," Mr Noda told a Cabinet meeting.
The government's official endorsement of the claim by Tokyo Electric Power Company (Tepco) that the reactors have reached cold shutdown status is a necessary step toward revising evacuation zones around the plant and focusing efforts from simply stabilising the facility to actually starting the arduous process of shutting it down.
But its assessment has some important caveats.
The government says Fukushima Dai-ichi has reached cold shutdown "conditions" - a cautious phrasing reflecting the fact that Tepco cannot measure temperatures of melted fuel in the damaged reactors in the same way as with normally functioning ones.
Even so, the announcement marks the end of the second phase of the government's lengthy road map to completely decommission the plant, which is expected to take 30 years or more.