A Japanese parliamentary panel is to release its report into the handling of the nuclear disaster at Fukushima, after months of hearings.
The report is expected to be critical of both government officials and plant operator Tokyo Electric Power.
Meanwhile, the first nuclear reactor to be switched back on since the March 2011 disaster has started generating electricity.
The restart, ordered by PM Yoshihiko Noda last month, was met with protests.
More than 20,000 people were killed when the earthquake and tsunami struck north-eastern Japan.
The six-reactor Fukushima Daiichi nuclear plant was badly damaged, in what was regarded as the worst nuclear disaster since Chernobyl in 1986.