They were found civilly liable.

“At the time of the disaster, Japan’s nuclear regulator was severely criticised for its collusive ties with the nuclear industry, resulting in the formation of a new watchdog that has imposed stricter criteria for the restart of nuclear reactors that were shut down in the wake of the Fukushima disaster.”

“Collusive ties”

“The ruling echoed the conclusion reached by an independent parliamentary investigation, which described the Fukushima Daiichi meltdown as a “man-made” disaster caused by poor regulation and collusion between the government, Tepco and the industry’s then watchdog, the nuclear and industrial safety agency.”