Japan's nuclear authority on Wednesday effectively determined that two units at Kansai Electric Power Co.'s Oi plant on the Sea of Japan coast have met the country's safety standards, paving the way for the return of more reactors.

That brings the number of reactors that have met the standards, adopted after the 2011 Fukushima nuclear disaster, to 12 at six power stations. After seeking public feedback, the Nuclear Regulation Authority is expected to give its final approval as early as April, officials said.

Ahead of the planned restart of the Oi plant's No. 3 and 4 reactors in Fukui Prefecture, which may happen as early as this summer, Kansai Electric will undertake disaster-prevention measures, including construction of a wall to protect the facilities against tsunami. The operator still needs to obtain local approval.