* Tepco gets OK to apply for Kashiwazaki Kariwa restart
* Restart a core of Tepco's revival plan after Fukushima
* Regulator's approval for restart uncertain, could take months
Tokyo Electric Power Co took an initial step forward on Thursday in its plan to recover from the Fukushima nuclear disaster by winning approval from a previously reluctant local governor to apply to restart a plant in western Japan.
Getting the green light to seek safety approval for the Kashiwazaki Kariwa facility, the world's largest nuclear plant, is a core element of the utility's turnaround plan as it struggles to contain contaminated water at the wrecked Fukushima plant.
All of Japan's 50 reactors were shut down after the 2011 earthquake and tsunami crippled Fukushima, and triggered a nuclear crisis, amid a wave of public revulsion against the industry. Two units were brought back on line last year, but shutdowns in recent weeks have left Japan without nuclear power for only the third time since 1970.
The return to power last year of Prime Minister Shinzo Abe, a proponent of nuclear power who says Fukushima is "under control", has given rise to suggestions that idled reactors may be restarted under safety guidelines. The process is expected to take well into next year.
Tokyo Electric, known as Tepco, said it would approach Japan's new nuclear regulator on Friday to seek permission to restart two of seven reactors at Kashiwazaki Kariwa, 300 km (180 miles) northwest of Tokyo.
The governor of Niigata prefecture, in a statement issued a day after a highly publicised appeal from Tepco's president, said he was allowing the utility to apply for safety approval. But he was withholding final judgment on restarting the plant.
"Kashiwazaki Kariwa nuclear power plant may be halted but it is a living facility, and safety must be ensured at the plant," Governor Hirohiko Izumida said in a statement faxed to Reuters.
There was no immediate explanation for the change of heart by Izumida, who had previously denounced Tepco as unfit to run a nuclear plant and had called for the company's liquidation.
Approval from the Nuclear Regulation Authority, established after its predecessor was discredited by the 2011 disaster, is uncertain and any decision could take many months at best.
On Wednesday, NRA Chairman Shunichi Tanaka declined to comment on prospects for a restart of Kashiwazaki Kariwa.
The nuclear shutdowns have obliged Japan to import costly fuel to meet its power needs. The country has run trade deficits for 14 months, the longest string since 1979-80.
Tepco is already behind schedule on its revival plan, which called for firing up at least one Kashiwazaki Kariwa reactor by April of this year. If all seven reactors were operational, Tepco says, it would save the company $1 billion a month in costs to generate power for Japan's biggest economic region.
Tepco president Naomi Hirose said in a statement that the company would uphold its safety commitments. On Wednesday, he told Izumida the company would attach a second filter to ease pressure inside containment vessels if an emergency arose.
The 2011 disaster knocked out cooling systems at Fukushima, provoking meltdowns in three reactors, the worst nuclear accident since 1986 in Chernobyl.
Tepco has had to acknowledge that radioactive water has been leaking into the Pacific, practically since the accident. During a tour of the plant this month, Abe said he had told Tepco to set a time frame for dealing with the leaks.
Four other electric utilities have sought NRA approval for restarts, which must also be approved by local authorities.