By Kentaro Hamada and Mari Saito
FUKUI, Japan (Reuters) - A Japanese court will rule on Tuesday whether to block the restart of nuclear reactors in western Japan on safety grounds, in a case that could complicate Prime Minister Shinzo Abe's push to return to atomic energy after the 2011 Fukushima disaster.
Local residents have sought an injunction against Kansai Electric Power Co, arguing that restart plans underestimate earthquake risks, fail to meet tougher safety standards and lack credible evacuation measures.
Four years after a quake and tsunami wrecked the Fukushima plant, leading to meltdowns and mass evacuations, four reactors at two power stations in south and west Japan have cleared all major technical hurdles. Opponents see the courts as their last hope to block the revival of unpopular nuclear power.
A three-judge panel is to rule on the injunction request against Kansai Electric's Takahama reactors west of Tokyo at 0500 GMT (0700 BST).
The head of the panel, Hideaki Higuchi, is regarded as a maverick in the conservative judiciary. He ruled against the restart of another Kansai Electric plant in May last year. Legal efforts by Kansai Electric to have Higuchi and the two other judges on the panel removed failed last week.
A ruling on a similar injunction against a Kyushu Electric Power Co plant in southern Japan is scheduled for April 22, and activists have vowed to fight the restart of any other reactors that clear regulatory safety tests.
Injunctions could mean months, even years of delays and hundreds of millions of dollars in losses for the two utilities. For Abe, resuming nuclear power - which supplied nearly one-third of Japan's electricity pre-Fukushima - is key to lifting the world's third-biggest economy out of two decades of anaemic growth.
Two of the Takahama reactors, with a capacity of 870-megawatts each, have received the first approvals in a three-step process and may restart later this year, unless the court blocks this.
A ruling against the reactors could keep the restart tied up in years of litigation as Kansai Electric would have to lodge a time-consuming appeal if the injunction is granted. It may also affect the outcome of other rulings in a country that was the third-biggest user of atomic energy before Fukushima.
Kansai Electric, Japan's most nuclear dependent utility before Fukushima, forecasts an annual loss of 161 billion yen (0.91 billion pounds) because of the cost of burning fossil fuels for power generation, bringing losses since Fukushima to 744 billion yen.
The company, which raised prices by 14 percent this month for its corporate customers, serves Japan's second most important economic region, where companies including Panasonic Corp and Sharp Corp are headquartered.
Japan's biggest business lobby, Keidanren, is a strong supporter of a return to nuclear power and wants power bills cut, but Abe needs to tread carefully because opinions polls show consistent public opposition to nuclear power.
Japan's judiciary - which typically sided with power companies before the Fukushima disaster - may be shifting its attitude.
In ruling against Kansai electric's Ohi plant, Higuchi delivered a scathing critique of the risk management of Japan's nuclear industry.
Judges are now considering injunctions that could halt the restarts and indefinitely extend the countrywide shutdown of Japan's 43 operable reactors.
Japan has been importing record amounts of liquefied natural gas and coal to fill the gap for power generation, pushing the country into a record deficits.
Imports of LNG and coal are expected to stay high unless Japan moves to start more than a few reactors.
(Reporting by Kentaro Hamada in Fukui and Mari Saito in Tokyo; Additional reporting and writing by Aaron Sheldrick; Editing by Ed Davies)