MATSUYAMA, EHIME PREF. - When two earthquakes of magnitude 6.5 and 7.3 struck Kumamoto Prefecture in April, the shock was felt not only in Kumamoto but also about 170 km away, in the small town of Ikata, Ehime Prefecture, home to a nuclear power plant.
For years, residents had been told that the Median Tectonic Line, which runs from Kyushu to Honshu and passes just 5 km away from the Ikata plant, was not active and that there was nothing to worry about. After the April quakes, no abnormal atomic activity was reported, but residents are now worried a large quake in the area, followed by tsunami, could not only damage the plant but also make evacuation from the peninsula Ikata lies on impossible.
The restart of Ikata reactor 3, slated for Aug. 12, has put those concerns in sharp focus and raised questions about just how realistic evacuation will be in the event of a natural disaster — especially an earthquake that sends a tsunami churning toward the nearly 124,000 residents living within 30 km of the plant.
“The official evacuation plans assume emergency vehicles will have a certain degree of access to the low-lying roads on the peninsula, which are often only a few meters above sea level. But what happens if the roads are flooded by tsunami or damaged beyond use due to landslides? There are about 5,000 people on the peninsula living on the western side of the Ikata plant who might be cut off from escaping by land to the designated evacuation areas lying east of the plant,” said Tsukasa Wada, an Matsuyama-based antinuclear activist who is fighting to keep the Ikata plant closed.
In granting permission last year to restart Ikata’s No. 3 unit, Ehime Gov. Tokihiro Nakamura dismissed such concerns, saying the rock formations around the plant are strong. But the prefecture has designated 194 areas in the town of Ikata as highly susceptible to landslides.
To get to the Ikata plant from Matsuyama by car or bus also involves passing through a series of tunnels. Tunnel construction experts have testified in past lawsuits involving the plant that many of the tunnels are weak, suggesting that an earthquake could cause cave-ins, rendering them unusable.
The central government and the prefecture are aware that land evacuations alone could prove impossible. So the official plans also include evacuations by air and, most controversially, by sea. The plans assume there is time to evacuate by sea before radiation from the plant spreads, and that ships can dock at nearby ports even if the peninsula’s main access road has been destroyed by a quake, tsunami, or both.
The April quakes in Kumamoto led to fears in neighboring Kagoshima Prefecture about running the two reactors at Kyushu Electric Power Co.’s Sendai plant. That helped fuel the election last month of Gov. Satoshi Mitazono, who is against nuclear power and has said he’ll try to shut down the two Sendai reactors.
But in late July, Ehime Gov. Nakamura insisted that, despite the results in Kagoshima and growing concerns in Ehime, where an opinion poll by the daily Ehime Shimbun in July found 54 percent of respondents opposed to the restart, he had no intention of canceling or postponing it to revisit the issues of the plant’s safety or the evacuation plans.
“The conditions are different in each of the different areas where nuclear power plants are located, as is the age of the reactors in each area and their structure. You can’t compare them. In particular, for the process leading up to restarts, the approach and system is different for each area, with different plans for evacuation,” Nakamura told reporters at a regular press briefing.
But even a Shikoku Electric Power Co. survey in late May and early June of nearly 28,000 households lying within 20 km of the Ikata plant showed that, compared with a similar survey last year, more people were skeptical of safety assurances and fewer were convinced of the need for nuclear power. Shikoku Electric admits that the Kumamoto earthquakes probably influenced this year’s results.