The magnitude 6.8 earthquake that hit the northwest coast of Japan Monday morning is rocking the country's faith in its nuclear power plants, raising questions about the safety of facilities that provide a third of the energy consumed by the quake-prone archipelago.
The death toll from the temblor, which shook Niigata, Nagano and Toyama prefectures, was nine as of Tuesday, with one person reportedly still missing. That's far less than a 2004 quake that struck the same area and killed more than 60 while leaving 16,000 homeless. But instead of feeling relief, the entire country has been rattled by TV images of black smoke billowing from Niigata's Kashiwazaki Kariwa nuclear power plant, located just 9km (5.6 miles) from the epicenter in the Sea of Japan. The plant suffered a string of problems when the temblor struck. Tokyo Electric, the Kashiwazaki plant's owner/operator, was quick to point out that a smoky fire that broke out in an electric transformer posed no threat to the rest of the facility and was extinguished in a few hours. Three of the seven reactors were inactive due to periodic inspections, the company said, and four others stopped automatically, as they are programmed to do during strong quakes.
But as the day went on, it became clear that more had gone wrong than was originally disclosed. Some 1.2 tons of radioactive water used to cool the reactors had spilled, the company suspects, from a spent-fuel pool and into the nearby ocean. Tokyo Electric also announced that 100 drums containing radioactive solid waste were toppled, and some radioactive material was detected in one of the main exhaust pipes that emit the plant's treated emissions into the open air. Prime Minister Shinzo Abe criticized the company for failing to respond quickly enough in the quake's aftermath. Tokyo Electric President Tsunehisa Katsumata apologized, saying "We were not aware of the dangers." He added that Monday was a national holiday, which delayed the assembly of response teams.
The amount of radioactivity escaping into the environment from the water and exhaust leaks was reportedly minuscule and posed no threat to people or the surrounding area. But questions are being raised over the safety of 16 other nuclear plants located throughout Japan, a nation that lies atop numerous active fault lines. The intensity of Monday's quake was 2.5 times the level the power plant's structures were built to sustain without any damage.
"Just because the quake was double the quake-resistant standard, it doesn't automatically mean a threat," says Shuji Kawahara, an earthquake safety inspection official in the Ministry of Economy, Trade and Industry's nuclear safety department. "The structures are built to withstand much much more," he said. How much more? "We don't know," says Kawahara.
It's the unknowns that worry regulators and experts. "Yesterday's quake showed that assumptions and suppositions that safety standards are based on are completely false," says Baku Nishio, a co-director at Citizen's Nuclear Information Center. "Japan is simply too quake-bound to operate nuclear plants." There's also uncertainty about where the next quake will strike. The Kashiwazaki facility underwent a tectonic survey last year to reevaluate the site's quake resistency and update it in accordance with new government guidelines. That survey concluded there were no active faults in the vicinity.
But because Japan depends heavily upon nuclear power for electricity, it's unlikely much can or will be changed. "Building a reasonably quake-resistant plant is way too costly to be truly realistic," says Hiroyuki Nagasawa, a management-systems professor at Osaka Prefecture University. "Nothing short of reevaluating our energy policy will change the current situation, but we have much bigger political powers working to keep the plants running." The country has been spared a quake-related nuclear calamity so far. Citizens can only hope their luck holds.
With reporting by Yuki Oda/Tokyo