The New York Times (pg. A3)  [Printer-friendly version]
July 25, 2007


By Martin Fackler

Tokyo, July 24 -- After a deadly earthquake struck northwestern Japan
last week, the nation was stunned by widespread damage to a nuclear
power plant near the quake's center, including minor radiation leaks,
ruptured pipes, flooding and a fire that belched black smoke for more
than an hour on live television.

But perhaps the most startling discovery occurred in the days that
followed, when scientists used data from the magnitude 6.8 earthquake
on July 16 to conclude that the Kashiwazaki-Kariwa plant, the world's
largest by electrical output, may have unknowingly been built directly
on top of an active seismic fault. That could account for the force of
the tremors, which Tokyo Electric Power, the operator of the plant,
said were more than twice as strong as the plant's design limits.

The earthquake, which killed 11 people and destroyed hundreds of homes
in Kashiwazaki, a city nearby, has raised discomforting questions
about the safety of nuclear plants in Japan. The plants in this
earthquake-prone nation are supposed to be nearly earthquake-proof,
built to withstand the most powerful punch. The Kashiwazaki plant's
surprising vulnerability to damage, however, has distressed many

The damage at the plant appeared to offer a vivid reminder of the
risks of nuclear power, as the United States, Europe and countries
elsewhere are giving atomic energy a second look as a clean, plentiful
alternative to oil and other fossil fuels. Resource-poor Japan kept
building nuclear plants even after accidents like Three Mile Island in
1979 in the United States and Chernobyl in 1986 in Ukraine froze
construction in the United States and parts of Europe for decades.

Nuclear experts applaud the fact that all four of the Kashiwazaki
plant's seven reactors that were operating when the earthquake struck
were safely shut down, despite the unexpected strength of the tremors.
But Tokyo Electric's failure to predict the size of the tremors that
could strike the area, and to detect the fault line beneath the plant,
left many here wondering whether regulators and plant operators could
also have underestimated the potential for devastating earthquakes at
Japan's 48 other nuclear reactors.

"The plant did an excellent job of ensuring the safety of the
reactors themselves," said Michio Ishikawa, president of the Japan
Nuclear Technology Institute, a research group sponsored by the
industry. "But how could they have not known about the active fault

On Tuesday, the Ministry of Economy, Trade and Industry, which
oversees energy policy, said it would create an independent panel of
academic experts to investigate the damage at the Kashiwazaki plant in
Niigata Prefecture. The panel's findings will be presented to the
International Atomic Energy Agency, a United Nations group that will
send its own inspectors to the plant, the ministry said.

The discovery of the fault line has attracted intense news media
attention in Japan, partly because it echoes problems at nuclear
plants elsewhere in Japan. Lawsuits have sought the closure of at
least four other plants because of nearby fault lines. The plants
include one in Shika, a town in western Japan, where a large fault was
discovered in 2005, just before the plant was completed.

The earthquake last week also defied expectations by moving
differently from previous quakes in the region, Tokyo Electric said.
The Kashiwazaki plant was designed to withstand shorter, more intense
tremors. But the recent quake struck with a broad, wrenching
horizontal swaying that caused water to slosh out of storage pools.

About 317 gallons of this spilled water, contaminated by tiny amounts
of radioactive material, reached the nearby Sea of Japan. Tokyo
Electric said the levels of radioactivity in that spill and a separate
leak of contaminated exhaust were far too low to harm the environment.
It also said damage at the plant had only occurred in less critical
areas, which had been built to less stringent standards than the
reactors, which were housed in bunkerlike concrete buildings.

Tokyo Electric admitted that it had failed to find the fault where the
earthquake occurred. The company said the fault line did not show up
in surveys of the area made in the late 1970s, when it started
building the plant.

But the company says the plant is still safe because the fault line
appears to lie more than 12 miles beneath the plant, too deep to cause
the sorts of big cracks and other surface movement that could damage
the reactors' thick concrete buildings.

"Not finding the fault was a miss on our part," said Toshiaki Sakai,
who leads the engineering group in charge of Tokyo Electric nuclear
plants. "But it was not a fatal miss by any means."

Still, critics say the fact that the miss could happen at all points
to a bigger problem: the broad discretion that the government gives
power companies in deciding whether a site is safe.

Katsuhiko Ishibashi, a professor at Kobe University specializing in
earthquakes and urban safety, was a member of a committee that set new
earthquake safety guidelines for Japan's nuclear reactors last year.
He said some of the committee's 20 members were scholars and engineers
with close ties to power companies, including one who advised those

Mr. Ishibashi said the guidelines, approved in September, were too
vague and left too much discretion to power companies in deciding
whether a plant site was seismically safe. He said he got so angry at
the lack of discussion in the committee about the new guidelines that
he resigned in disgust at the final meeting.

The strength of the earthquake in Kashiwazaki "could have been
predicted, and should have been predicted," Mr. Ishibashi said. "The
new guidelines are very insufficient and have loopholes."

Plant operators and government regulators call those criticisms
unfair. They say the companies' plans face intense scrutiny from
committees of independent scholars. They also say the Kashiwazaki
plant was just unlucky: The earthquake struck a year before Tokyo
Electric was to finish a seismic survey to ensure that the plant met
the standards of the new earthquake safety guidelines.

"The company did the best it could with the technology that it had
available when the plant was constructed," said Hitoshi Sato, deputy
director general for nuclear safety at the Ministry of Economy, Trade
and Industry. "If you insisted on being 100 percent sure about
finding all active fault lines, you'd never get anything built."