Brace for big quake

A magnitude 5 earthquake was detected in waters off the southeastern city of Ulsan on Tuesday evening. The quake was Korea's fifth largest since the nation began keeping relevant records in 1978.

The tremor was felt across the southeastern region, including Busan and Gyeongsang provinces. The earthquake shook some buildings in Ulsan and Busan, which were close to the epicenter, prompting some movie theaters to halt screening. Fortunately, there were no reports of casualties or damage.

What made people worry all the more was that the southeastern region is densely studded with nuclear power plants. Currently, the Gori 1 to 4 reactors are located in Gijang County, Busan, and there are four other reactors in Ulsan, two of which were completed last year and are currently on test runs. The fifth and sixth units are also to be built there.

In the event of a bigger earthquake, no one can rule out the possibility of a catastrophic nuclear accident. In fact, nearly 5 million people are living within a 50-kilomter radius of the Gori nuclear power plant.

Many experts play down the chances of large-scale earthquakes in Korea, saying fault lines near the Korean Peninsula are not inter-connected. But a growing number of experts have been voicing concern that the peninsula is no longer safe from earthquakes that have a magnitude of 5 or higher. According to the Korea Meteorological Administration, a total of 1,212 quakes have been detected since 1978, with six of them having a magnitude of 5.

The government approved the construction of the fifth and sixth reactors at the Ulsan complex last month. After Tuesday's earthquake, an opposition lawmaker vowed to file an injunction seeking the cancellation of the construction permits.

However, given the country's long-term energy supply and demand outlook, it's too premature to demand the revocation of the new nuclear reactors plan merely out of vague safety concerns. This is all the more so, considering that it is increasingly difficult to build thermal power plants because of environmental problems.

Our nuclear power units are designed to withstand a quake with a magnitude of up to 6.5, and new reactors can withstand a magnitude of 7. The nuclear regulator says these criteria are strong enough to withstand quakes that could hit the peninsula.

But the nuclear disaster in Fukushima shows that we cannot overstate the importance of safety in atomic power plants. Needless to say, safety measures related to earthquakes must be prepared on the assumption that conditions are the worst. 
http://www.koreatimes.co.kr/www/news/opinon/2016/07/202_208857.html