The Fukui District Court ordered the operator, Kansai Electric Power Co, not to restart the No 3 and No 4 reactors at the Takahama plant in Fukui prefecture, which is home to about a dozen reactors.
The court criticized the Nuclear Regulation Authority's safety standards for being too lax even with stricter requirements imposed following the Fukushima crisis after the March 2011 earthquake and tsunami.
It said meeting the new standards does not guarantee the safety of the Takahama reactors.
A group of residents and their supporters requested the injunction, saying a massive earthquake exceeding the facility's quake resistance standards could cause tremendous damage to the region, similar to the Fukushima crisis.
The first two reactors, in southern Japan, scheduled to go back online have also received regulatory approval and are making final preparations toward a planned restart in the summer. But there is also a separate injunction request before a court seeking to halt that.
