Ulsan storage tank explodes, 6 deadAn explosion at a chemical factory in the southeastern coastal metropolis of Ulsan killed six and injured one on Friday.
The blast was set off at a plastic plant run by Hanwha Chemical, the chemical and auto parts branch of the conglomerate Hanwha Group, in the country’s seventh-largest city located 190 miles southeast of Seoul.
The explosion occurred at around 9:20 a.m. during welding work to increase pump flow on a storage tank in a wastewater disposal facility. Hanwha Chemical said in a statement that two of the six who died that morning were directly involved in the work, while the four others were assistants.
All six were hired through subcontractors. The injured person was identified as a 52-year-old male security guard surnamed Choi.
The precise cause of the blast is under investigation, but firefighters, Hanwha Chemical insiders and officials from the Korea Gas Safety Corporation suspect that a welding spark might have come in contact with an unknown source of residual gas in the storage tank.
What made the accident especially deadly, they said, was that the entire upper part of the concrete tank exploded.
At 5 meters (16.4 feet) high, the tank had a capacity of 700 cubic meters (7,535 cubic feet) and was used to dispose of wastewater from the manufacturing process of synthetic resins.
A safety check was performed before the welding to measure gas concentration around the area and find any flammable materials, an employee from Hanwha Chemical said on condition of anonymity.
The company, however, failed to inspect the interior of the tank because “it was completely sealed,” the source added. “It’s normally impossible for a flammable substance to penetrate a 20-centimeter-thick (8-inch-thick) concrete tank.”
But in a country just recovering from an outbreak of Middle East respiratory syndrome (MERS), blamed on sloppiness of medical personnel and an insouciant attitude toward public safety, Park Dal-jae, a safety engineering professor at Seoul National University of Science and Technology, insisted the argument was nonsense.
“To state that the company overlooked a safety check on the inside of the tank because it was enclosed,” said Park. “Just goes to show how utterly ignorant it was about safety.”
The professor said the source could hardly be serious about the tank being completely sealed and suggested that the accident could almost have been expected.
Over the past five years, nearly 200 accidents have occurred in the Ulsan Mipo National Industrial Complex, home of Hanwha Chemical and some 900 other companies. At least five were killed in that period before Friday’s accident.
BY LEE SUNG-EUN, YU MYUNG-HAN and CHA SANG-EUN [firstname.lastname@example.org]