Japan has launched a new nuclear oversight agency following criticism that collusion between regulators and plant operators contributed to meltdowns at the tsunami-stricken Fukushima Dai-Ichi plant.
Japan began reviewing its energy policies following the Fukushima crisis.
Before the accident, resource-poor Japan relied on nuclear power for one-third of its energy and had planned to raise that to 50%.
Officials said the five-member Nuclear Regulation Authority, headed by nuclear physicist Shunichi Tanaka, was inaugurated after months of delay due to opposition.
Last week a Cabinet advisory panel proposed a new national energy policy aimed at phasing out nuclear power over the next three decades.
The Cabinet was due to approve the policy today but reports said members would endorse only some aspects of the sweeping policy revisions.