Japanese nuclear plant 'shutdown'

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.