Hokkaido Gov. Harumi Takahashi on Tuesday urged the central government to address local safety concerns about the Oma nuclear power plant project, the subject of a lawsuit filed against the government by the city of Hakodate.

"We want the state to take seriously the fact that Hakodate has filed a lawsuit and sincerely respond to local concerns," Takahashi said in a request to the central government.

She also called for "prudence" in regard to the Oma plant, which is being built in Aomori Prefecture and will be the world's first reactor to run solely on plutonium-uranium mixed oxide fuel, or MOX, which contains weapons-grade plutonium.

Takahashi, however, remained vague about whether she would support the project if the government made a convincing case.

The lawsuit, filed by the city of Hakodate in April, marks the first time a local government has taken legal action against the central government to halt a nuclear power plant.

Although the city of Hakodate lies roughly 23 km across the ocean from the Oma plant, which is being built on the northernmost tip of Honshu, there is a high chance that an accident there would threaten it with radiation if the winds are blowing in that direction.

The Hakodate government has said the impact of an accident at the "full-MOX" reactor would be far more devastating than the Fukushima disaster because its core will contain a large amount of highly toxic plutonium. MOX fuel is produced from uranium and plutonium extracted by reprocessing used uranium. It plays a central part in Japan's fuel recycling policy.

Some reactors in Japan have allowed MOX to make up one-third of their cores, but the Oma plant will be the first in the world to solely burn MOX.