TOKYO - Reconstructed documents show Japanese leaders knew hours after the tsunami that the Fukushima nuclear power plant's reactors could melt, but kept their knowledge from the public for months.

Then-Prime Minister Naoto Kan at one point feared the crisis could turn worse than Chornobyl. The revelations were in documents disclosed Friday, almost a year after the disaster.

The minutes of the government's crisis management meetings from March 11 to late December were not recorded and had to reconstructed retroactively.

They have added to sharp public criticism about how the nuclear crisis was handled.