This handout photo released by the French Institute for Radiological Protection and Nuclear Safety (IRSN) on Dec 19, 2013, shows Tokyo Electric Power Co (TEPCO) Kashiwazaki-Kariwa nuclear power plant at Kashiwazaki city in Niigata prefecture, northern Japan. (PHOTO / IRSN VIA AFP)

TOKYO - Tokyo Electric Power Co said on Thursday it had applied for regulatory approval to load nuclear fuel into reactor No. 7 at its Kashiwazaki-Kariwa power station from April 15 as it seeks to restart the world's biggest nuclear plant.

The Kashiwazaki-Kariwa plant has been offline since 2012 after an accident at another Tepco plant in Fukushima a year earlier led to the shutdown of all nuclear plants in Japan at the time.

Tepco needs consent from Niigata prefecture, where the plant is located, to resume operations

Japan's nuclear power regulator in December lifted an operational ban on the Kashiwazaki-Kariwa plant. Tepco is counting on a restart of its only operable nuclear power station as the utility looks to slash its operating costs.

Tepco needs consent from Niigata prefecture, where the plant is located, to resume operations. The prefecture governor said last week more talks were needed over the possible restart, suggesting operations may not resume quickly.

Shares in Tepco rose 6 percent in early trading on the news, first reported by local media on Thursday, but later eased to trade up 4.1 percent. The Nikkei index, opens new tab was down 1.2 percent.