[Yonhap News Photo]
SEOUL -- South Korea's first geothermal power plant was suspended under an order from a court which ruled in favor of citizens stricken by a series of earthquakes and ceaseless tremors in the southeastern city of Pohang.
In its ruling on Wednesday, the court in Pohang asked Nexgeo Inc. to suspend the operation of its geothermal power plant until government officials and civilian experts complete their one-year site assessment that began after a 5.4-magnitude earthquake hit Pohang about 270 kilometers (167 miles) southeast of Seoul in November last year.
The quake triggered numerous aftershocks, leaving about 60 people injured. Safety concerns grew after the city was rattled by a 4.6 magnitude quake in February. Citizens filed for an injection to stop the operation of the geothermal plant, and international and domestic experts were brought in for seismic analysis.
The plant capable of creating 6.2 megawatts of electricity is under test in a place two kilometers away from the epicenter.
"I think the geothermal power plant had an impact. I don't believe it occurred just due to the geothermal power plant, but it may have provided fodder for the earthquake," Kim Gwang-hee, a Pusan National University professor, said in a seminar Wednesday.
Compared to conventional geothermal plants which run on steam from within the earth, enhanced geothermal has been mentioned as a source of inexpensive energy, but scientists argue drilling deep to tap naturally occurring heat could cause earthquakes.
The technique involves the injection of high-pressure water into a hole drilled deep into hot rocks. As water forces its way into the Earth's crust, it carves new fractures into the rock and absorbs heat. Then engineers simply pump the heated water back to the surface and use the resulting steam to turn turbines.
Geologists insist the water-infusion step will create some seismic activity but the tremors can cause real damage as drilling-induced fractures can interact with existing seismic systems to produce quakes.
A geothermal project in Basel, Switzerland, which drilled 4.8 kilometers into the Earth's crust, set off an earthquake, leading to the shutdown of its operation. Drilling has been fingered as the cause of a massive 2006 mud volcano in Java.
Lee Jin-han, a geology department professor of Korea University, said in a TV interview in November last year that two holes have been drilled to a depth of 4.5 kilometers for the plant in Pohang. "I'm not 100 percent sure, but the possibilities are quite large," Lee said, supporting a theory that the plant may have been related to a series of quakes in Pohang.
reporter
Lim Chang-won
cwlim34@ajunews.com
