The nuclear power plant that spreads along the shoreline of this earthquake-prone region presents a conundrum. It sustains this town and endangers it, and residents and officials say they are uncertain whether to push for safer nuclear plants or oppose them altogether.

Omaezaki’s concerns serve as a suitable stand-in for a national problem. The Hamaoka nuclear plant here provides 1,296 jobs in this town of 36,115, southwest of Tokyo. But the plant is menaced by Japan’s most notorious fault line. Earthquakes occur here every 100 to 150 years, seismologists say. The last so-called Tokai earthquake was 157 years ago.

As the central government reconsiders its policy on atomic energy, which calls for the construction of 14 new reactors by 2030, people in the coastal towns that host Japan’s 17 nuclear stations are likewise rethinking the dangers, with governors in at least three prefectures calling for drastic safety overhauls or freezing plans for more reactors.

In Omaezaki, a move away from nuclear power would come at a cost. The town receives plant-related subsidies that account for 42 percent of the annual budget. Anytime a new reactor gets built, Omaezaki receives money from Tokyo. According to town officials, Omaezaki has used its subsidies to build its roads, library, hospital, schools and a swimming pool.

But this week, a Kobe-based seismologist, Katsuhiko Ishibashi, called Hamaoka “the most dangerous nuclear plant not just in Japan but in the world.” Several dozen residents here have spent nearly a decade pursuing a lawsuit that calls for the plant to be closed immediately, finding little traction for their argument.

Before the Fukushima plant’s partial meltdown clarified the hazards of nuclear power, Omaezaki’s mayor, Shigeo Ishihara, told anybody who would listen that the local plant was safe. Even in an earthquake, he said, radioactive material could be cooled and contained.

“We haven’t always been an aggressive promoter of nuclear power plants,” he said, “but we had gone along with the plan.”

That changed March 15, four days after this country’s greatest natural disaster in nearly a century. At a news conference, Ishihara for the first time expressed reservations about a project that called for injecting mixed plutonium-uranium oxide fuel, known as MOX, into one of Hamaoka’s reactors.

For Ishihara, the sentiment was a costly one: Omaezaki stood to lose $47 million in subsidies, spread over seven years, if it rejected the plan. But two days later, Shizuoka prefecture’s governor, Heita Kawakatsu, endorsed the mayor’s concerns and canceled the government’s approval of the new power generation system.

Safety improvements

At a subsequent meeting at the Omaezaki town office, Ishihara discussed his broader concerns about Hamaoka’s safety with the president of the Chubu Electric Power Co., which operates the plant. The power company, in response to the March 11 9.0-magnitude earthquake, had already drafted several new safety measures for the Hamaoka plant.

Chubu presented Ishihara with a color-printed pamphlet explaining its ideas. The company would move its backup generator to a higher elevation, as protection against a tsunami. It would secure extra cooling equipment. And it would build a 12- or 15-meter breakwater wall, placing it either in front of or behind a man-made sand dune that is the facility’s only protection against a great wave.

Chubu’s president, as well as a local official from the Hamaoka plant, told the mayor that the wall could be built within three or four years.

Ishihara said that wasn’t good enough.

“I thought it might be rude,” Ishihara said, “but I told them flatly, ‘Do it without taking any time to sleep.’ Now that’s what they’re doing. We’ll be grateful if it’s completed in one year.”

Assessing the risk

Japan began to rapidly develop nuclear power in the 1960s, when the science of plate tectonics was still in its infancy. A more-detailed understanding of Japan’s seismic activity emerged only in time to illustrate the vulnerability of power plants that had been built or approved.

Hamaoka, approved for construction in 1970, sits on some of the world’s least stable land. Just offshore from the plant, the oceanic Philippine Plate is sliding beneath the continental Eurasian Plate. Pressure is building. Japan’s government anticipates that the next Tokai earthquake will have a magnitude of at least 8.0. A Chubu spokesman, Akio Miyazaki, said Hamaoka has been designed to withstand at least an 8.4-magnitude quake.

Chiyoka Tsukamoto, a member of the citizens group that launched the Hamaoka lawsuit, traveled to an anti-nuclear rally last weekend in Tokyo and described the scenario of a major earthquake to 2,000 people.

For a decade, Tsukamoto, who lives 17 miles from Hamaoka, had researched the fault lines and dangers. She had pushed for meetings with local authorities, generally finding them “indifferent” to her concerns, she said. She had traveled the region with petition forms and learned that even those who feared the plant weren’t willing to oppose it. Restaurant owners and hotel operators, for instance, depended on Hamaoka for business.

But starting March 11, Tsukamoto’s cause gained a wider audience.

“At the bottom of the ocean, there is a huge amount of energy that has accumulated,” Tsukamoto, standing atop a stone ledge, told the crowd last weekend. “If that energy is released, the power plant that stands right in front of it could be in huge crisis. This is something even an amateur would know.”

In the past month, the Omaezaki town office has received 390 phone calls, faxes or e-mails expressing concern about the plant. But the mayor, in his second term, hasn’t called for the plant’s closure. Ishihara said of his situation that he is “stuck in between,” trying to balance the town’s safety and its economy.

“Next year, there will be a mayoral election here, and for sure, there will be an anti-nuclear candidate,” he said. “This will be the biggest issue here.”

Special correspondent Akiko Yamamoto contributed to this report.