Japanese nuclear plants sit atop ‘unstable region’: report

Two nuclear power plants in Japan are located right on top of a seismically unstable region, raising the possibility of an earthquake-induced disaster, according to a report on Wednesday.

Tomari plant in Hokkaido and Tsuruga plant in Fukui Prefecture sit on active faults, the Japanese media reported, citing a report by Japan’s Nuclear and Industrial Safety Agency.

The fault under the Tsuruga plant is believed to have moved some 4,500 years ago, according to Kyodo news agency. The underground layers in the region are fractured zones created by the movement of active faults, making the area susceptible to earthquakes in the future.

This means the Tsuruga plant may be forced to shut down soon because the Japanese government forbids nuclear reactors from being built on faults that have the potential to cause tremors.

Tsuruga plant’s operator Japan Atomic Power Company denied that the plant was a risk, stressing that the fault under the nuclear reactor has never caused quakes before.

However, the fact that it has no history of quakes does not guarantee safety, given that a massive aftershock that followed a devastating 9.0 temblor in Fukushima Prefecture last March occurred on a fault that was thought to be stable.

Japan is located in the “Ring of Fire” region that encircles the Pacific Ocean, and accounts for about 20 percent of the world’s earthquakes of magnitude 6.0 or greater.

Massive earthquakes and a tsunami last year caused explosions at the Fukushima nuclear power plant about 220 kilometers northeast of Tokyo. It is considered the worst nuclear disaster since Chernobyl.

By Yoon Min-sik (minsikyoon@heraldcorp.com)