Tepco's Kashiwazaki-Kariwa station, the world's biggest nuclear power plant, may get initial safety approval from Japan's nuclear regulator next week to restart two reactors, the Yomiuri newspaper and other media reported.

Approval would allow a company that has been widely criticized for a lax approach to safety and a slow response to the meltdowns at Fukushima to operate a nuclear power station after regulators earlier questioned if it was up to the task.

A go-ahead would also be the first for reactors of the same basic design as those that melted down at the Fukushima Daiichi station in March 2011, after a massive earthquake and tsunami knocked out cooling and power systems.

Radiation from the meltdowns forced 160,000 people from their homes, many never to return, and destroyed businesses, fisheries and agriculture. The latest government estimate puts the cost of the disaster at 21.5 trillion yen (150.98 billion pounds).

After reports of the possible approval for Kashiwazaki-Kariwa, Tepco shares rose as high as 450 yen, up 15 yen, or 3.4 percent. They were up 2.8 percent at 0416 GMT, while the broader market was up 0.1 percent.

A Tepco spokesman declined to comment on the reports. The company has said it could save up to 10 billion yen ($92 million) a month in power generating fuels for each reactor it restarts at Kashiwazaki-Kariwa.

Hurdles remain to any restart, the biggest being getting approval from the governor of Niigata prefecture, where the Kashiwazaki plant is located.

Ryuichi Yoneyama, the governor, has said he will not discuss a restart until Niigata completes its own safety review, which could take until 2020 at the earliest.

Tepco has said it will cooperate with the prefecture's review for Kashiwazaki, which is also the world's biggest power station in terms of capacity outside of hydroelectric dams.

Many of Japan's nuclear reactors are still going through a relicensing process set up after the Fukushima disaster, the world's worst since Chernobyl in 1986.

Five out of 42 reactors are now operating after reviews, the most since the Fukushima disaster led to the eventual shutdown of all nuclear units.

All of the restarted units have a different design from those at Fukushima, using a technology that some experts say make them less susceptible to meltdowns.

(Reporting by Aaron Sheldrick and Osamu Tsukimori; Editing by Tom Hogue)