Atsuko Ogasawara has watched a nuclear power plant be built from her yard for the past five years. Her choice to remain in her home is driven by her determination to carry on her late mother’s fight against nuclear power. (Chico Harlan and Yuki Oda/The Washington Post)

At the remote northwestern tip of a snowy peninsula, beyond a small road of fishing shacks and empty one-story homes, 600 construction workers and engineers are building a brand-new nuclear plant for a country still recovering from the most severe atomic accident since Chernobyl.

The main reactor building is already at its full height, though draped in heavy fabric to protect it from the wind and freezing temperatures. A 500-foot crane swivels overhead. A completed power line stretches along a nearby ridge, where it might one day carry electricity down the peninsula and back toward the Japanese mainland — a place still fiercely divided over the long-term role of nuclear power.

In the aftermath of March 2011 meltdowns in Fukushima that contaminated 700 square miles with radiation and forced 150,000 to flee their homes, most never to return, Japan’s utility companies paused nearly all nuclear-related projects. The accident sparked a global debate about nuclear power, but it was especially fierce in Japan, where all 50 operable reactors were taken offline and work was halted on three new plants where building had been underway.

But two of the existing reactors are back in action, and the resumption of construction at the Oma Nuclear Power Plant here — a project that broke ground in 2008 and was halted by the operator, J-Power, after the accident — marks the clearest sign yet that the stalemate is breaking.

The green light for the new plan was, at its root, a bet by the energy company that Japan will come to again support and rely on nuclear power, which provided some one-third of Japan’s electricity before the Fukushima crisis.

Analysts say that predicting the direction of Japan’s atomic future is difficult and that J-Power’s decision is a risky one — even with a ­pro-nuclear party back in power — because a majority here opposes long-term nuclear dependence.

Still, experts see modest evidence of nuclear power’s resiliency. Japan has traditionally built its nuclear plants in far-flung towns that depend on the facilities for the subsidies and tax dollars — as well as the jobs — they bring. Consumers and big businesses fear the long-term economic pain of a nuclear phaseout — increased dependence on imported fossil fuels, annual trade deficits, higher energy bills.

At the national level, Japan has cycled through three prime ministers since Fukushima — the first fiercely anti-nuclear, the next moderately anti-nuclear, the current one cautiously pro-nuclear. The previous ruling party tried last fall to plot a nuclear phaseout by the 2030s, but anti-nuclear advocates say the pledge was watered down to the point of being meaningless. The new prime minister, Shinzo Abe, plans this month to convene the latest in a series of expert panels to help overwrite the phaseout plan, and its makeup suggests that he prefers a role for nuclear power.

Japan’s anti-nuclear movement, which swelled after the Fukushima accident, could still play a role, but it is politically disorganized and has grown quieter in recent months. Individual activists cite the resumption at Oma as controversial but note that the move did not prompt mass-scale protests.

“Right now, the trend is not going in the right direction,” said ­Misao “Redwolf” Shinoto, a leader of the anti-nuclear movement.

Work stoppage

By March 2011, construction at Oma was more than one-third complete, with a 2014 target date for commercial operation. But J-Power voluntarily halted the project after Fukushima. Contractors were sent home or told to find new work. Twenty-three cranes were disassembled and shipped out. Only a skeleton staff stayed behind in Oma. And for the next 18 months, J-Power waited to see whether Japan’s central government would reconsider its long-term commitment to nuclear power.

Gradually the country’s 50 working reactors were shuttered, because of safety concerns or for routine maintenance checks. Two reactors in western Japan restarted in July, but others remain in limbo, requiring major reinforcement against earthquakes, tsunamis and other disasters.

Oma, a fishing town of 6,200, had sought a nuclear plant since 1976, when an official with the chamber of commerce wrote to the mayor saying it was time to “reconsider the fundamental industry in Oma.”

Decades passed before construction began, with delays caused by changes in reactor design and location, but during that time J-Power won support in the town. The company hired three or four local high school graduates every year. It helped fund a new community center with a library, an indoor sports complex and a swimming pool. It sponsored local fireworks shows.

Those in Oma largely maintained their backing for nuclear power post-Fukushima, looking with detachment at 100,000-strong anti-nuclear protests in Tokyo and watching with concern as then-Prime Minister Naoto Kan, in July 2011, said nuclear power was a risk Japan couldn’t afford.

Roughly 15 percent of the town’s annual budget comes from government subsidies handed down for its willingness to host the plant. Phasing out nuclear power would be a “sorry thing,” said Oma’s mayor, Mitsuharu Kanazawa.

For its part, J-Power would sustain a “major financial blow” if it could not operate the Oma plant, spokesman Hiroshi Nakatani said in a February interview, though he refused to provide specifics.

With its hydro and thermal stations, J-Power generates 6 to 7 percent of Japan’s power, which it sells to the country’s nine regional utility monopolies. That supply has become even more important post-Fukushima, as those monopolies have less generating capacity of their own.

But J-Power has long coveted nuclear power, seeing it as potentially cheaper and more environmentally friendly than coal imports, and Oma is its first nuclear project.

Their timing “was terrible,” said Hiroshi Takahashi, an energy industry expert at the Fujitsu Research Institute in Tokyo. “If I can make some advice to J-Power, it is to get out of nuclear power right now before they encounter even more problems.”

J-Power, two company spokesmen say, never considered abandoning the Oma project. The company’s announcement to resume construction came on Oct. 1 — just 12 days after the government’s vague pledge to phase out nuclear power by the 2030s.

J-Power officials and ­then-energy minister Yukio Edano say there was no conversation between the government and the company about the resumption. But company officials say they took it as a sign of government approval when Edano visited Aomori prefecture — home of Oma and several other atomic facilities — in mid-September and said he would not stand in the way of construction that had been approved pre-Fukushima.

A nuclear reactor can go online in Japan only after an elaborate series of agreements from the host town, surrounding communities and central government. Before it can begin operations, the first reactor at Oma, a 1,383-megawatt advanced boiling-water reactor, must secure another round of approvals and meet still-unfinalized safety standards. J-Power does not have an estimate for when the reactor at Oma will be completed.

For some anti-nuclear activists and politicians, the construction of a new reactor is particularly worrying because it gives Japan the potential to operate plants into the late 2050s, far beyond the 40-year life span of already completed reactors. Two other reactors were under construction at the time of the Fukushima accident, and at neither has building resumed.

“We should give up building new nuclear plants,” Kan, who served as prime minister during the disaster, said during an interview in his office, a photo of a wind farm hanging on the wall. “If we cannot get rid of the risk [of an accident], the safest alternative would be a society without nuclear energy.”

A power shift

J-Power’s decision came as polls showed growing support for the traditionally pro-nuclear Liberal Democratic Party (LDP), which claimed a landslide victory in December parliamentary elections and installed Abe as its prime minister. Abe on Feb. 28 said he would seek to restart existing reactors once the country fosters a “new culture of safety” with new measures enforced by a beefed-up regulatory agency.

The new government could, theoretically, order all plants to shut down by the 2030s; in that case, nuclear power would act only as a bridge, providing power while Japan builds up alternative sources. It could also revamp the phaseout pledge created by the previous government and allow the plants to run for much longer — not just as a stopgap but as a core pillar. That would also require the construction of new reactors, and experts say finding towns willing to accept the projects could be a challenge, with towns not yet dependent on the nuclear industry wanting little to do with it.

The LDP has said nothing specific about such long-term plans. And even if the party drafts such plans, they could prove irrelevant if the LDP falls from power. But analysts point out that the LDP is Japan’s mainstream party, running the country for most of the past six decades and now reestablished with Abe’s approval rating above 70 percent.

Looking for some clarity, Oma’s mayor, along with the chairman of the chamber of commerce, Kiyotaka Denpo, and representatives from several other towns, traveled in mid-February to Tokyo for a meeting at the Ministry of Economy, Trade and Industry.

They asked the officials to continue to promote nuclear power, Kanazawa and Denpo said. They also asked the government to build a wider and more direct route heading out of town, to enable speedy evacuation in case of emergency.

Finally, Denpo asked about whether the government intended to stick with the plan to phase out nuclear power by the 2030s, as the now-ousted Democratic Party of Japan had called for.

A ministry spokesman declined to say what the group talked about.

The answer Denpo says he heard assures nothing, but it made him feel better about the direction in which Japan was heading.

“I asked them, ‘So, are you going to get rid of nuclear plants by the 2030s?’ ” Denpo said. “And they said no.”

Yuki Oda contributed to this report.