CNG Fuel Tanks Recalled Following Explosion in Cheongju

A recall is scheduled for bus fuel tanks using compressed natural gas made before February 2005.

The Knowledge Economy Ministry yesterday said it investigated a CNG fuel tank explosion that occurred on July 12 in Cheongju, North Chungcheong Province, and decided to recall 9,200 of the fuel tanks by April next year.

Subject to the recall is about 10 percent of the country’s 15,000 CNG-powered buses. The ministry and related companies said the explosion happened in a bus standing at a depot in Cheongju after filling its tank.

No casualties were reported, but the bus suffered major damage and flying debris destroyed nearby buildings and vehicles as far as 250 meters away.

The explosion was the third since CNG-powered buses were introduced in 2000. In 2005, similar explosions occurred in January and August.

At the time, the then Commerce, Industry and Energy Ministry convened an investigation team after the second explosion. The task force disposed of 4,500 fuel tanks manufactured around the same time the exploded one was and ordered the remaining 9,200 tanks to be reused only after passing strict examination.

In this year’s explosion, the fuel tank in question was one of the 9,200 tanks approved for reuse. A Knowledge Economy Ministry official said, “When the fuel tanks were examined, they showed no problems in quality. But repeated fill-ups of gas might have caused cracks inside the fuel tanks.”

Some experts warn that the planned time period for the fuel tank change is too late. They say another explosion is likely over the next nine months, given that the three previous accidents came every seven months.

sunrise@donga.com