Japan’s government was to declare Friday that the tsunami-devastated Fukushima Dai-ichi nuclear power plant had finally achieved a “cold shutdown,” meaning it has stabilized and is no longer leaking substantial amounts of radiation.

The announcement would mark a big milestone nine months after the March 11 tsunami touched off a crisis at the plant and sent three of its reactors into meltdowns. Experts noted, however, that the facility remains vulnerable to more problems and will take decades of difficult and dangerous work to safely close down.

Prime Minister Yoshihiko Noda was to announce the government’s assessment of conditions at the plant in a news conference later Friday.

The government’s official endorsement of the claim by Tokyo Electric Power Co. that the reactors have reached cold shutdown status is a necessary step toward revising evacuation zones around the plant and focusing efforts from simply stabilizing the facility to actually starting the arduous process of shutting it down.

But the assessment has some important caveats.

Full Story: Japan set to declare nuclear plant stable

Source: Associated Press/Google News