The Nuclear Regulatory Authority (NRA) on Wednesday gave the OK for Shikoku Electric Power Co to restart the No. 3 reactor at its Ikata nuclear power plant in Ehime Prefecture.
The safety approval is still only one of three needed before the reactor can go back online. The consent of local authorities, which is seen as a formality, is also required, along with operational checks.
The NRA signed off on a provisional assessment that the Ikata reactor meets new design standards introduced after Fukushima.
The decision will be a boost for operator Shikoku Electric, which relied on Ikata -- its sole nuclear power plant -- for about 40% of its electricity output before the meltdowns at Fukushima led to the shutdown of all the country's reactors.
The Ikata No. 3 reactor started operations in 1994 and has a capacity of 890 megawatts.
The future of the Ikata plant's two other reactors, each with capacity of 566 megawatts, is unclear. One is almost 40 years old, which is the lifetime limit for reactors in Japan without a special extension that will be costly to achieve.
Shikoku Electric hasn't applied for restarts of that reactor or the No. 2 unit, which began operations in 1982.
For the government of Prime Minister Shinzo Abe, resuming nuclear power, which provided about a third of Japan's electricity supply before Fukushima, is key to lifting the economy out of two decades of anemic growth.
The country has switched to fossil fuels to compensate for the closure of reactors, pushing imports of liquefied natural gas to a record-high 7.78 trillion yen in the financial year ended March 31.
Four other reactors operated by Kansai Electric Power and Kyushu Electric Power have passed through the first stage of regulatory checks.© Japan Today/Thomson Reuters